For her Earth Two counterpart, see Caitlin Snow (Earth Two).
For her Earth Fifty counterpart, see Caitlin Snow (alternate).
"Right, I'm the queen of letting these people down. But you know what? They're still here. No matter how much I disappoint them, they still show up for me. I don't really understand it, but I think that's part of this whole friends thing. So, unless you do something worse than kidnap and stab them, I think you're gonna be just fine."
— Killer Frost to Ralph Dibny

Dr. Caitlin "Cait" Snow  is a female Human in the 24th century who is a former scientist at Mercury Labs and a former bio-engineer at S.T.A.R. Labs. She was working during the particle accelerator disaster and tended to Barry Allen during his coma with Cisco Ramon until he woke up. After he began his crusade as "The Flash" Caitlin became a member of his team with Cisco and Dr. Harrison Wells, before discovering the latter's identity as Eobard Thawne, and provides medical support for the team. Caitlin is also the wife of the late Ronnie Raymond, and is close friends with Cisco, Barry, Felicity, Typhuss and Ralph Dibny. She is also the former lover of "Jay Garrick", before discovering his true identity as Hunter Zolomon and the former girlfriend of Julian Albert.

In the Flashpoint timeline, Caitlin is not a scientist but is a doctor who is unwillingly brought into Ramon Industries by Barry to help him restore the timeline. Following Barry's attempt to restore the timeline, Caitlin is once again a scientist at S.T.A.R. Labs, but also seemingly from changing time again she is also a meta-human with abilities similar to her Earth Two doppelgänger, who she is afraid of becoming like. However it's also implied that she could have been affected prior to Flashpoint. After being taken over by her rising anger while using her meta-human powers, losing control of her emotions, she briefly started going by her doppelgänger's name Killer Frost.

After suffering a clinical death from a seizure and subsequently being revived by her regenerative powers, her biochemistry was altered, culminating in her becoming fully consumed by her anger as Killer Frost, later encountering and allying with Savitar after the proclaimed speedster god reveals his true identity as a future version of Barry Allen. Later, between Cisco giving Caitlin the choice to cure herself rather than force it on her and watching Savitar nearly kill him, Caitlin finally regained her true personality and control of her powers. Despite this, Caitlin decided not to take the cure. Feeling lost to her own identity, Caitlin left Team Flash on good terms to rediscover herself. Six months later, having seemingly come to terms with her mistakes as Killer Frost, Caitlin finally decided to return to Team Flash, only to discover that her Killer Frost-side had returned.

Shortly after returning to Team Flash, Caitlin once again began to struggle with her Killer Frost side and eventually lost control. Iris West convinced both Caitlin and Killer Frost that they could try to be the same person instead of choosing one life or the other. As such, when preparing to serve as back up to Barry along with Cisco she stated "Snow and Frost standing by" emphasizing that both Caitlin and Killer Frost were prepared to work together to help. When Nazis from Earth-X tried to invade Earth One, she aided her friends in the battle that followed, earning Mick Rory's affection.

Early lifeEdit

From a young age, Caitlin idolized her parents who were both doctors and was inspired to follow in their footsteps. Growing up Caitlin practiced the Hippocratic oath and was obsessed with it. She grew to value life so much she wouldn't even let anyone step on a bug if she could help it. From a young age Caitlin was very close with her father but he suffered from multiple sclerosis. Her mother Carla Tannhauser tried to save him as he fought it for years but he eventually died, much to Caitlin's heartache. Following her father's death Carla began focusing only on her work as a way to cope with losing her husband, but her neglect of Caitlin left them estranged for several years.

In high school, Caitlin was bullied by Lexi LaRoche who put chewed bubble gum in her hair.

In adult years Caitlin became a trained neurosurgeon but was still estranged from her mother. Despite being estranged Carla still offered Caitlin a position at Tannhauser Industries but Caitlin wanted to make a name for herself and declined. Some time before 2377 Caitlin was hired at S.T.A.R. Labs by Dr. "Harrison Wells". Sometime after this she met Ronnie Raymond a structural engineer who in contrast to Caitlin's guarded outlook was more outgoing. Caitlin would later describe them as being "Fire and Ice". Despite being very different the two fell deeply in love and started dating. Though she enjoyed working at S.T.A.R. Labs she, like most employees, was often irritated by Dr. Wells' protege Hartley Rathaway.

Around 2378, Caitlin went out of town for their one year anniversary with Ronnie. Before leaving she met newly employed engineer Cisco Ramon after witnessing him debate engineering with Hartley. Cisco and Caitlin became close friends and he would consider her and Ronnie family, as he was estranged from his own and looked up to the couple. Eventually Ronnie proposed to Caitlin and she accepted. However she apparently never told her mother as she wouldn't even be aware Ronnie existed until over 1 year after his actual death.

Return of Killer FrostEdit

Caitlin almost kills Nigel

Killer Frost almost kills Nigel in a fit of rage

Whether as the result of Flashpoint or not, Caitlin developed cryokinesis meta-human powers akin to those of her Earth Two counterpart. She kept this a secret from the rest of the team, using them to help Barry escape Mirror Master's mirror trap. However, she later noticed while taking a shower that some of her hair turned pale blonde; she promptly cut off the altered hair to hide her powers. Desperate to understand what was happening to her, Caitlin visited her mother but was quickly annoyed when she asked if Caitlin had received her birthday card which she confirmed, in April, presumably a significant amount of time before or after it. Caitlin inquired how to get an appointment with her for a friend, not ready to reveal her secret, but as Carla coldly walked her through the procedures Caitlin angrily froze her desk and revealed she was the patient. Carla subsequently canceled all her appointments for the day and readied various tests for Caitlin. While preparing she met Carla's assistant Nigel. Caitlin was brought down to the facility's testing lab for molecular motion where she revealed a shaft made of solid tungsten, heated to over 2000 degrees centigrade. Carla asked Caitlin to freeze it in order to determine how to reverse what's happening to her. To her horror she froze it solid within seconds. After Caitlin revealed the origin of her powers, she and Carla fought over Caitlin working at S.T.A.R. Labs rather than Tannhauser Industries, which Caitlin reminded her was because she desired to make a name for herself. Before they could argue further Nigel came back with the results and revealed that Caitlin had not just frozen the tungsten but had absorbed all the energy it was emitting. However Caitlin was frustrated when she heard them talking about how her power could benefit their pursuits rather than offer sympathies. When Carla began taking blood samples Caitlin, finally having had enough, confronted her over he seemingly lack of care for her well-being and how she hasn't expressed any concern over her well being since her father died. Carla defended that she tried to save him and reminded Caitlin that she ran away but Caitlin told Carla that she had to because she wouldn't even so much as look at her. Carla accepted Caitlin's anguish and admitted that she got consumed in her work out of grief but scolded Caitlin, believing she didn't know what that kind of loss feels like. Outraged, Caitlin told Carla about Ronnie, who Carla didn't even seem to be aware of.

Killer Frost worried

Caitlin grows worried

Having had enough, Caitlin decided to leave but Nigel trapped her in the facility wanting to exploit her powers for himself. As he grabbed her Caitlin's inner Killer Frost persona was released in a fit of pure rage and she grabbed Nigel and froze his arm solid. Carla came into confront her, and Killer Frost ordered her mother to move, but Carla offered her apologizes, acknowledging that she wasn't much of a mother, but was steadfast that she didn't raise a killer, managing to talk her out of killing Nigel as mother and daughter hugged. Caitlin returned to help Team Flash stop the supposed monster roaming the city, only for it to be a hologram. Caitlin later told Cisco about visiting her mother and he commended her for trying to make amends with her family. Later Carla contacted Caitlin via webcam and told her that her results proved unfruitful; that Caitlin's biology was rapidly changing and the more she used her powers the less control she'd have. After hearing this, Killer Frost's anger emerged again, as Caitlin has accidentally frozen her desktop monitor, horrified to see that she was losing control over her emotions along with her growing meta-human powers. Worried of her powers, Caitlin stole power dampeners from S.T.A.R. Labs, something that Cisco thought to blame on H.R. Wells. She was seen wearing the dampeners during an attack of the meta-human Shade. After Cisco accidentally vibed Caitlin in the guise of Killer Frost, he forced her to reveal the truth about her powers to the team.

Killer Frost mid-transformation

In her first attack as Killer Frost, Caitlin still retained most of her natural looks, not fully transformed yet

Caitlin said she wouldn't save Barry from Savitar, for fear of using her powers and unleashing her Killer Frost side, and only went after Iris begged her. And after using her powers to save Barry from Savitar; unfortunately, she ended up dominated by her worry and anger, turning into Killer Frost. She went after Dr. Alchemy in an attempt to rid herself of her powers. She tricked Joe into believing that Wally has emerged from his cocoon, trying to divert Joe from the interrogation of one of the acolytes of Alchemy. She tortured the acolyte, but before she could extract any useful information, Caitlin was forced to flee by approaching SCIS officers, leaving the acolyte frozen. Still obsessed with finding Alchemy, Killer Frost kidnapped Julian Albert, forcing him to create a search algorithm to find Savitar's acolytes. Julian succeeded in locating a member of Alchemy's cult, but also alerted the SCIS to Killer Frost's location, as she tried to kill him. However, The Flash arrived and attempted to talk Caitlin down, even knocking out Albert to permit them to speak freely. Unfortunately, Caitlin was unable to control her powers; too far gone and panicked, she stabbed him in the leg and went after one of the acolytes, Craig. Upon arriving, she threatened the man's family, forcing him to comply. He informed Killer Frost that he didn't know where Alchemy was, or who he was, but only that Alchemy was merely another acolyte of Savitar who had shown them the future where, among other things, Caitlin had become Killer Frost. However, before she could press for more info on how to take away her powers, Vibe arrived and, like Barry, attempted to talk her down, but Killer Frost attacked Cisco. Barry then arrived on the scene and knocked Killer Frost to the ground. Unwilling to surrender, Killer Frost gave Barry a kiss, using her powers to freeze him solid. Luckily, Cisco was fast enough to smite her with a Vibe burst, knocking Killer Frost unconscious. Upon waking up in the Pipeline, Killer Frost attempted to convince Team Flash she was back to normal, to no avail. She then made an offer of leaving them alone, if they release her and allow her to go on her way. But Barry refused to abandon her, angering Frost. She yelled at him, blaming Barry rightly for everything bad that happened to the team after Flashpoint. Barry returned, asking for Caitlin's help with a freed Wally West, who couldn't maintain control over his powers. Killer Frost taunted Barry, who released her on one condition: if she wanted to leave, she had to kill him. Killer Frost threatened to do so, producing an icicle, but was unable to kill her friend. Crying, Caitlin finally snapped out of her anger and she hugged him, horrified at her actions. Barry comforted her and she went back with him, assisting the team in returning Wally to normal (albeit now with Super-Speed). Barry quit his job to save Caitlin from a life in prison after pleading with a furious Julian Albert, who would not be swayed to keep her secret unless Barry resigned from his work as a CSI, and she never thanked him for this.

Erased futureEdit

According to Craig, a member of Savitar's cult, Caitlin would have been described as being "glorious and powerful", and Savitar had "special plans" for her, which did come true as she helped him and he needed her to kill Black Flash.


During a joint mission with the Legends to stop the Dominators' invasion, Caitlin mostly partnered up with Professor Martin Stein, who encouraged her to learn how to control her powers, instead of denying them, just like he did as Firestorm. On her end, Caitlin helped Professor Stein to accept his daughter, Lily Stein, who was born as a result of an accidental temporal aberration.

Defeating AlchemyEdit

After the Flash has defeated Alchemy and took the Philosopher's Stone to S.T.A.R. Labs safe in its compartment box, Savitar tried to manipulate Cisco Ramon into taking the stone for himself and releasing him, appearing to Cisco in the guise of his late brother, Dante Ramon. Despite being threatened by Cisco not to approach him, Caitlin managed to talk him down and persuade to hide the Brahmastra, stopping Savitar again. Later on, Caitlin was present when Team Flash communicated with Savitar, possessing the body of Julian Albert. She was worried as he claimed a prophecy for Team Flash, saying that one of them would fall, the other betray them, and the other would suffer a fate worse than death. After this ordeal, Caitlin encouraged Julian to come celebrate Christmas together with Team Flash at West house, later on congratulating the CSI specialist when he came to the party after all. Showing Cisco that she took Martin Stein's advice to heart and started to practice control over her powers, Caitlin removed her power dampener and produced an icy mist with her hand, turning a raincloud above West house into a cloud of white snow.

Attack on S.T.A.R LabsEdit

A mysterious future villain of the Flash named Abra Kadabra appeared, stealing from several tech companies in an attempt to build a timeship to return to the 64th century. Abra Kadabra soon found himself chased after by the Flash and Gypsy, escaping, but not before telling Flash that he knew Savitar's name.

Sometime later, he teleported into S.T.A.R Labs and ambushed Caitlin, Julian and Joe West, but was soon apprehended by the Flash and locked up in the Pipeline, taunting the team about his knowledge of Savitar. There, he told Joe that if he let him escape from Gypsy, he promised to reveal Savitar's name so the team could save Iris. Joe agreed, and set him free, but Kadabra betrayed him, claiming that the terms of the agreement had changed. He then went to collect a mysterious future power source from the Time Vault, and set off an explosive as the trio attempted to chase after him upon his escape. The resulting explosion impaled Caitlin's side with shrapnel. Team Flash took her to the med bay and helped her onto the bed. Caitlin showed signs of physical pain, as she was breathing heavily and moaning. Cisco tried to stop the bleeding with a T-shirt while the team decided how they was going to help her. Julian X-rayed her and found she had bits of metal wedged inside her that needed to come out. Caitlin refused to go to the hospital as they will find out about her Killer Frost identity. Iris told the team that Caitlin couldn't operate on herself but Caitlin said she could if she had a mirror, she could talk someone through the surgery. Soon after Caitlin talked Julian though her own surgery. Iris helped stop the bleeding as Julian operated. As Julian came to the last piece of metal he found that it was stuck, as he tried to get it out, Caitlin's heart rate began to increase dangerously, causing Cisco to worry. Julian told her it was going to hurt as he pulled the metal out, Caitlin screamed in severe pain before becoming light headed and telling Julian to stitch her up as she was going to pass out. Not too long after she woke up in the med bay bed with Julien holding her hand. Julian told her how brave he thought she was before getting up to kiss her, but pausing out of fear of hurting her. Later that day, Cisco was alone with Caitlin. She seemed to be recovering well, but as they were talking, Caitlin stopped mid-sentence and passed out. She started seizing. Cisco panicked and called for help. Julian came running in with H.R. and they tried to hold her down, but she suddenly stopped. Cisco put his hand above Caitlin's mouth and found that she wasn't breathing. Julian began giving her compressions and told Cisco to get the oxygen mask and place it over her mouth. They then tried electric shock, but everything was unsuccessful. Julian tried more compressions while Cisco continued giving her oxygen but Caitlin wasn't responding and they couldn't resuscitate her. Cisco started crying, realizing his best friend had died. Julian, distraught, ripped off Caitlin's necklace, hoping her meta-human powers could regenerate her. About 30 seconds later, she began breathing again. Caitlin's wound also healed instantly, but she emanated a cloud of mist, sending the team and herself flying. Once the cloud cleared, Caitlin had transformed into Killer Frost and attacked the team before escaping.

Erased futureEdit

When Barry visited a possible future, in the year 2397, it is revealed that Caitlin allied herself with Savitar. Moreover, during a climactic battle, Vibe's arms were frozen and shattered by Caitlin, forcing him to replace them with bionic arms and subsequently making him unable to use his powers. Caitlin, still as Killer Frost, has been locked up in Iron Heights, and still refuses to divulge the identity of Savitar, with Julian as her caretaker.

Alliance with SavitarEdit

Caitlin wandered around in the snow, only to encounter Savitar. She asked if Savitar wanted to cure her, to bring Caitlin Snow back, but the armored villain wanted just the opposite. Caitlin then asked Savitar why should she trust him. To prove that he can be trusted, Savitar removed his armor and revealed himself as a future version of Barry. Seeing that, Caitlin agreed to do anything he wants.

She was sent by Savitar to the Central City University in order to kill future physicist Tracy Brand, however her attempt on the scientist's life was thwarted by the intervention of Barry and Cisco. She returned to Savitar to tell him of her failure. Savitar questioned Frost's loyalty by pondering the idea that there may be more Caitlin Snow still within her than she led him to believe, especially due to the fact that despite taking up the name Killer Frost she had not yet actually killed anyone. He then told her to once again try to kill Tracy with the promise that if she succeeded they could both be gods.

A few hours later she kidnapped Cecille at the West house and told Joe that the only way to spare Cecille's life would be to trade her for Tracy. At the site of the trade off she battled both Barry and Cisco before being overcome by Cisco's powers and knocked unconscious. Cisco then acquired a blood sample from her that Julian hoped could be key, due to Caitlin undergoing a full mutation into Killer Frost, to reversing the process and cure their friend. Before the team could return to Star Labs, to presumably lock Frost away in the Pipeline for their and her own safety, Savitar appeared and escaped with the still unconscious Killer Frost.

When Savitar lost his memory, Killer Frost realized that Team Flash erased Barry's memory to prevent the future Savitar is trying to create; but this also caused Wally to lose his powers. She offered them the hard choice of returning Barry's memory or leaving Central City vulnerable to attacks by meta-human criminals. Cisco encouraged her to remember being Caitlin Snow, which allowed her to help restore Barry's memory in surgery. She prepared to leave, with Julian confessing that he had fallen in love with her. This news briefly shocked Killer Frost, who coldly told the entire team she never loved them. When in the elevator, her eyes briefly returned to normal, showing that Killer Frost could be turned back into Caitlin.

In a news report on a screen reporting the arrest of Jared Morillo that Barry saw during his accidental trip to May 2390, a subheading read "Killer Frost still at large". While Barry succeeded in altering the circumstances of Morillo's arrest, with Wally defeating him instead of Barry in January instead, Caitlin's future remained the same. Barry later reveals to Joe that Caitlin's on the loose and they need to bring her in, prompting him to alert the CCPD. This causes the aforementioned headline.

Killer Frost was later seen talking to Savitar about his plans if he's really ready to end his former lover's life. He then stated that "It's either her or me", and that when the time comes she should be ready to do her part. When Savitar captured Iris HR Wells risked his life to stop him he switched appearances with her, so when Frost attacked them she didn't realize that she was actually taking back HR. Caitlin then met Vibe in a snowy forest area and said that she needs to "cure herself of Caitlin" and the only way to do that is to kill him. As the fight went on Killer Frost gained the upper hand. Right before Frost could finish off Cisco, Savitar appeared and stated she should keep him alive, as he needs him to modify the Speed Force Weapon. Later on, after Vibe finished making the modifications, Savitar ordered Caitlin to kill Cisco, which she tried to do, but Gypsy interfered and the two escaped.

Caitlin leaves Team Flash

Caitlin leaves Team Flash

Killer Frost then helped Savitar get rid of the Black Flash, and then used the weapon on the God of Speed. While interrupted by Team Flash, she took on Gypsy and Vibe but was subdued. Cisco then offered Killer Frost the choice to use the cure and become Caitlin again or remain in her current state. When Savitar attacked Cisco and attempted to kill him, Killer Frost, without using the cure, managed to take control of herself and let go of the mad persona. She attacked Savitar and watched his defeat by Barry and Iris. Caitlin later attended the funeral of HR Wells, where she met Julian and Cisco. She told them about her decision to leave, in the hope that she can rediscover herself. They bid each other goodbyes, and departed on good terms.

Rediscovery and returnEdit


Norvok, Caitlin's contact in Amunet's organization

Trying to find her own way in life, Caitlin left Team Flash and journeyed away, trying to stay undetected. Staying low profile, she didn't use her many doctorates to get a high paid job, but worked as a waitress in a bar instead. During her stay away from S.T.A.R. Labs she was contacted by Norvok, a member of Amunet Black's organization, and worked for them. During Samuroid's attack on Central City Cisco vibed Caitlin's location and visited the bar she worked in. She smirked at the thought of Barry still being stuck in the Speed Force. Cisco managed to convince her to return back to the team, where she helped Cisco in locating and later diagnosing Barry. Rejoining the team, Caitlin worked on helping to get Barry back to sanity, including using the speedster weapon to stop his mad rampage. Reuniting with Barry, apologizing before Joe and trading banter with Cisco, - all of it influenced Caitlin into leaving her job and coming back to S.T.A.R. Labs. She informed her associates at the bar about her decision to leave and was confronted by Norvok, who tried to strong-arm Caitlin into staying, threatening her for not listening to Amunet's orders. Angered by such an attack, Killer Frost used her meta-human powers to intimidate Norvok, nearly killing him via brain freeze. She was riled up enough to go "have some fun" on a rampage, but managed to force herself out of the violent mood, restoring her hair and eyes back to their natural color.


Caitlin Snow

Caitlin in her civilian persona

Caitlin is very intelligent and passionate about her work as a bio-engineer and scientist, even keeping a blood collection kit in her purse. She is generally a very compassionate and caring woman. She loved her fiancé Ronnie Raymond very much, he knew how to make her laugh and was devastated by his death which sent her into a state of depression for almost a year, because of this she didn't smile much. However. since being brought onto the team, working with Barry Allen, helping people and saving lives, she has started to liven back up. She has shown great concern for Barry as she often advises against engaging meta-humans they know little about and was initially against Barry using his powers as a guardian angel for Central City, though she eventually grew to accept and even participate in it.

Caitlin is also seen to be somewhat "guarded", in her own words, and timid as seen when she was terrified of going into the S.T.A.R. Labs particle accelerator it being the location of Ronnie's supposed death, though she later overcame this obstacle with Barry's support, becoming more assertive, brave and confident. Despite them being quite different in personality, she is also close friends with Cisco Ramon but finds his need to nickname every meta-human they face annoying, although she has occasionally nicknamed a meta-human now and then herself. Leonard Snart considers Caitlin to be "uptight," which his sister agrees with. When Caitlin was reunited with Ronnie, alive and well after he was separated from Martin Stein, she was overjoyed, no traits of her initial depressive, forlorn personality remaining. When she finally marries Ronnie, she is perfectly content accepting that everything she's experienced over the past year, leading up to wedding the man she loves has been worth it. When Caitlin loses Ronnie again, this time for real, Caitlin is devastated, so much she is unable to stay in S.T.A.R. Labs as she blames herself for his death. However she has slowly managed to recover and regained her desire to help Team Flash.

Though not as prominent as her other traits, Caitlin has a somewhat flirtatious side to her personality. Often when flustered or uninhibited by the effects of alcohol she can become silly, frazzled, and hinted a few times during her night out at the dive bar with Barry that she dropped many hints that she was interested in Barry. After meeting Hunter Zolomon, masquerading under the name "Jay Garrick", he and Caitlin have quickly become infatuated with each other, their infatuation developing into a relationship. Caitlin's love for Hunter was the driving force for her to find a cure for his condition. However, after the revelation of "Jay Garrick" as the man behind the mask of Zoom, Caitlin did not allow her feelings to cloud her judgment on Zoom's misdeeds, rightfully recognizing him as "nothing but a monster" and refusing to accept Hunter's lingering affection for her. Nevertheless, Caitlin called upon those feelings, her face in tears, when she tried to influence Hunter to show his merciful side, sparing Barry Allen from certain death.

After her imprisonment with Hunter, it seems that Caitlin is suffering from post traumatic stress disorder (PTSD), due to her former lover and his frightening behavior and repeated displays of violence in front of her, seeing visions of Zoom when he's not there, and questioning if she still has her sanity.

Since Caitlin has been developing cryogenesis/cryokinesis abilities like her Earth Two counterpart she has been terrified of becoming just like her. While reluctant to tell her friends she has used these powers to aid them occasionally without them knowing, but has gradually realized her inability to control them. This has made Caitlin very terrified but as a result of her changing biology she has become increasingly temperamental, which causes her appearance to become more like her Earth-2 counterpart. However Caitlin is still sane enough to realize this but is only more horrified at her increasingly inability to manage her emotions. However her desire to retain her humanity and her biology changing to make her more "cold", seems to be causing Caitlin to develop dissociative identity disorder.

Worrying about her new-found, uncontrolled powers, Caitlin's emotions become heightened enough that she became a vindictive, angry and cruel individual, similar, but not identical to Frankie Kane's split personality disorder. Also like Frankie, when affected by her powers, her eyes glow pale blue (while Frankie's glow pink). However, while Magenta tried to get rid of the Frankie persona altogether, Killer Frost state amplifies Caitlin's own fears, insecurities and bitterness. As Killer Frost, she mocked Barry by mentioning his most horrible failures including the deaths of his mother, father, Eddie and Ronnie, as well as revealing to Cisco that his brother, Dante was alive in the pre-Flashpoint timeline, before Barry changed it. She expressed bitterness over Barry only caring about himself and his own happy ending, while she was left broken.

Caitlin also mocked Cisco by calling him pathetic for feeling sorry that he had to hurt her to save Barry. She openly blamed Barry for what's happened to her, yet admitted that she feels broken. She nearly killed Julian and one of Alchemy's Acolytes, however she was still unable to kill Barry, making her snap out of her anger, as she became horrified at what she almost did.

Once Killer Frost was fully awakened due to Caitlin's temporary death and revival, she states that she doesn't want to be cured and wants Caitlin Snow never to come back. She allies herself with Savitar after he reveals himself to her.

Killer Frost went after Tracy Brand after Savitar promised that if she lives up to her name and murders Tracy, she could be a god. She arrived at CCU in her new outfit and attacked Barry and Cisco, but when Barry fought back with fire, she ran away. She then attacked Tracy for the second time outside Jitters and continuously formed an ice slide that she slid on for a while without any difficulty. She took advantage of the fact that Cisco would not hurt her and almost hit him with a blast that Barry took. She stabbed Barry in the leg so that he couldn't follow her and she left, claiming that this is her now.

Later, Killer Frost kidnapped Joe's girlfriend Cecille outside of Joe's home and threatened to kill her if Joe and the team did not hand over Tracy to her and Savitar. Later at the supposed exchange site, she claimed that killing Cecille would bring her no joy but Tracy's death at her hands would. When Barry tried to talk her out of it, she knew exactly what Barry was going to say. She and Cisco later faced off, and while she seemed calm at first, she later fought back as hard as she can and lost to him. Cisco managed to get a sample of her blood, which could be the key to making a cure for her. Before Cisco can take her, Savitar arrived and took her away.

Despite all this, while reluctantly working alongside her former allies, it was shown she still has a strong attachment to her memories of working at S.T.A.R. Labs when she and Cisco reminisced about Ronnie losing his temper back when they were trying to build the particle accelerator. However. Killer Frost also showed in this moment that thinking about who she used to be made her uncomfortable as she quickly, sullenly, stated that she didn't want to stay any longer than she had to. Her conflicted feelings about herself and her old allies was again emphasized when she told Team Flash she never loved them and left, only for the assertion to hurt her heart enough to cause the real Caitlin to emerge for a few seconds once she was out of the team's sight.

Despite her continued allegiance to Savitar, Caitlin began showing signs of regret and doubt in her betrayal. During the final confrontation of Team Flash and Savitar, Cisco's unceasing loyalty for Caitlin finally enabled Caitlin's true-self to become permanently restored and reconciled with her friends. At the same time, she felt lost, unsure of who she is now.

Six months after restored to Caitlin, Killer Frost became stronger and eventually was able to regain control in various occasions. Recently Killer Frost's personality became similar to Caitlin's. After Iris conviced Killer Frost and Cailtin that they could co-exist they decided be allies and not enemies. Despite them now being allies, Killer Frost severely dislikes the color pink, well Caitlin does not.

In the future in which Iris dies, by the time of the year 2397, Caitlin has become too far gone to the point where she refuses to be called real name, as she prefers being called by her alias "Killer Frost", she becomes angry when people call her by her real name, despite her insanity and cold nature, Caitlin is very observant; she was able to realize that the Barry Allen she was speaking to was the younger-self of her Barry; due to the look on his face, as the latter had not yet become emotionally broken, as his Iris was not dead yet. This future was later erased when Savitar killed H.R. instead of Iris.

Powers and abilitiesEdit


Caitlin produces icy mist with her hand

Caitlin produces icy mist with her hand

"My name is Killer Frost."
"Your name is Caitlin Snow."
"Can Caitlin Snow do
—Cisco Ramon and Killer Frost
  • Meta-human physiology: Prior to the Flashpoint event, Caitlin displayed no meta-human potential after being subjected to tests by several different sources. After the events of Flashpoint her powers developed, however, it is implied that her meta-human gene could have simply been dormant before.
    • Transformation: After Caitlin and Killer Frost decided to be just one, Caitlin became able to transform into Killer Frost and vice-versa.
      • Energy absorption/Cryokinesis: Caitlin's powers work by absorbing all existing heat around her, thereby reducing the temperature and to freeze targets well-below negative 370 degrees, even shattering beings as powerful as the Black Flash. Even more, her powers can reach such low levels that they can completely negate a speedster's healing powers and alternatively neutralize accelerated decomposing. Caitlin can create various ice structures with ease, even creating large bullet proof shields that can with standing point blank automatic rifle rounds, as well as launching upon manifestation sharp projectiles in rapid succession, creating an icy blade around her arm or as means of transportation, by producing icy waves of such propulsive strength, with one hand behind her, to propel herself forth across an ice slide she forms before her with her other hand, similar to Firestorm's fire-based propulsion ability. Her powers can also affect the weather around her, dropping the climate of the area and cause it to snow. She can also freeze objects without direct contact shown when she froze H.R's coffee from afar. A tell-tale sign of her accessing her powers is producing icy mist from her hands.
        • Accelerated healing factor: While accessing her powers, Caitlin's metabolic rate is augmented to offset cold tissue destruction, allowing her endure more grievous injuries and likewise heal much faster than even a speedster, though foreign matter must first be taken out to not impede the healing. After clinically dying from a combination of a seizure and her reopened impalement wound, she was immediately resuscitated into a stable and cognitive state while her wound seamlessly healed completely in seconds. However, her healing powers only work when her Killer Frost side takes over, as wounds inflicted by Amunet left bruising and required stitches. Interestingly enough, Caitlin's Earth Two doppleganger seemed to lack this aspect of their near-similar meta-human powers, which was what led to Earth Two Killer Frost's death at Zoom's hand.
        • Cold immunity: An added benefit to her powers, Caitlin also exhibits a high resistance to frigid temperatures. She is shown to be able to hold the ice constructs she manifests with little trouble. She was also seen unaffected after she escaped S.T.A.R. Labs, when there was a snowstorm.
        • Freezing breath: Caitlin is able to create a fog with her breath. Around six months following the defeat of Savitar, Caitlin, as Killer Frost, grew powerful enough to orally produce cold mists with enough momentum to knock back several people off their feet.


  • Computer specialist: As an member of S.T.A.R. Labs, Caitlin is shown to have some technological skills of note, albeit not her main area of expertise as was evident in her ability to reprogram S.T.A.R. Labs satellite to track meteorological abnormalities over Central City, so they could find the location of Clyde Mardon.
  • Expert medic: Caitlin is shown to be an expert in medical care, as seen when she was able to cure Barry Allen after he was poisoned by Kyle Nimbus, and later, when she was able to patch-up the former when he was seriously injured by Tony Woodward, Caitlin was also able to patch-up "Harrison Wells" after he was brutally beaten up by his Reverse-Flash speed mirage.
  • Genius-level intellect: Caitlin is very intelligent, having a PhD and two doctorates. Her talents have been a crucial aid in helping Team Flash. Also, she, along with Cisco Ramon, were able to create a cure for Mirakuru.
  • High pain tolerance: Caitlin is shown to have a remarkable level of endurance. Despite the grievous injuries she gained from Abrakadabra, she was able to maintain consciousness through the surgery to remove the shrapnel in her body, all while instructing Julian.
  • 'Hand-to-hand combatant: To a yet to be elaborated degree during the past six months since Barry disappeared into the Speed Force, Caitlin as Killer Frost, demonstrated a measure of sheer hand-to-hand combat when she reversed an arm bar exerted upon her and then slamming the guilty party responsible, pinning him painfully against a pinball machine. It was later revealed that she worked as an enforcer for Amunet Black's illicit activities during periods when Killer Frost was active, explaining Caitlin's newfound fighting skills whenever her other side takes over. Later, during the Earth-X crisis events, Caitlin was able to defeat several Nazi soldiers with an "ice sword" that she created around her arm.
  • Marksmanship: Armed with a Cold Gun, Caitlin displayed being able to incapacitate a crazed Barry running wildly around S.T.A.R. Labs despite the fact that the latter was accelerated in super-speed and much faster than ever before. Even Cisco admitted he couldn't have hit Barry moving that fast with a vibrational blast.


  • Carbine: Caitlin has implied that like her Earth Two counterpart, her powers have no effect on carbine.
  • Power-dampening tech: If Caitlin is wearing power-dampening cuffs, she can't use her powers.
  • Super speed: If a speedster brings Caitlin into "Flashtime", causing her to move as fast as a speedster, the amount of heat this creates makes it impossible for Caitlin to use her powers. Also, despite the fact the Caitlin's healing factor exceeds Barry's, it is unable to prevent her from becoming exhausted as quickly as a normal person would in "Flashtime".

Former weaknessesEdit

  • Julian Albert's serum: Julian worked with Caitlin's mother, Carla Tannhauser to create a serum capable of removing Caitlin's powers. According to Caitlin, while the serum initially seemed to work, Killer Frost reemerged sometime afterwards, stronger than before, and was no longer affected by the serum.
  • Borderline split personality disorder: Caitlin's changing biology also caused physiological effects. The more she would use her powers, the crueler and more sadistic she would become, showing no emotional attachment or regard for human life. While struggling to contain her powers, she developed a form of dissociative identity disorder which is triggered when angered, making it difficult to calm her down and restore her rationality. The change can be seen as the case of Caitlin's super-ego weakening in her psychic apparatus, allowing for her hidden fears, grudges and insecurities to come to the surface, rather than a true split personality. Over time, her friends continued trust and love for her finally let her overcome her mental damages, regaining her sanity while having full control over her power. However, six months later, having taken Julian's serum to cure her, it proved only temporary and had an additional side-effect of developing a complete separate personality. In addition to the changes happening more suddenly and erratically both ways, it also caused both the Caitlin and Killer Frost side to no longer have any recollection of the other's actions. After some words of inspiring encouragement from Iris, Caitlin and Killer Frost decided to just be the same person, Caitlin no longer had a problem with her Killer Frost side. Killer Frost eventually even starts to worry about Caitlin when faced with the threat of a nuclear explosion.
  • Limited/Unstable control of powers: According to her mother, the continuous use of Caitlin's powers would end up making her unable to "turn them off", leading to Caitlin accidentally freezing her laptop. Caitlin seemingly began to use her powers (in small doses) with no adverse effect, as shown at Christmas 2016 when she made it snow. A tell-tale sign of her powers overwhelming her are the physical changes she gradually gains from them, such as her hair turning white and lips turning blue. The most noticeable sign of her losing control is her eyes glowing a pale whitish-blue and her distorted voice. The physical changes become more prominent as she makes use of her abilities, though they will recede if she goes long enough without using them, such as her hair going from white back to its original chestnut brown. However, as Killer Frost she is in full control of her powers, to the point where she was able to create a slide of ice to ride across the city. Caitlin is now able to control them through her Killer Frost side, who has now become her ally.


  • Killer Frost suit: Caitlin wears a protective suit as her alter-ego, Killer Frost. After gaining full control over her powers and aiding her friends in the final battle against Savitar, she stops wearing it. However, after her Killer Frost side returns, Caitlin starts wearing a new protective jacket when she is in battle.

Former equipmentEdit

  • Power-dampening cuffs: After her powers began manifesting, due to her unstable control over them, Caitlin initially wore a pair of Cisco's power-dampening cuffs on her wrists as a means to help keep her powers in check. However, she abandoned use of these when she couldn't keep them charged for long periods of time and would have to sit with them plugged in, which she said made her "feel like a human tablet".
  • Solar power collection pendant: Julian made Caitlin a pendant designed to dampen her powers, as well as to collect solar energy in order to help charge it whenever she went outside, so that it continues to work without constant recharging. However, upon her temporary death, Julian removed it; as Killer Frost, she destroyed it.