Caitlin Snow


 * For her Earth Two equivalent, see Caitlin Snow (Earth Two).

"We may not be able to have a perfect Christmas, but we can have a white one."

- Caitlin "conjuring" snow with cryokinesis

Dr. Caitlin "Cait" Snow is a female Human in the 24th century who is a former scientist at Mercury Labs and a 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 and provides medical support for the team. Caitlin is also the widow of the late Ronnie Raymond, and is close friends with Cisco, Barry, Typhuss James Halliwell and Felicity Smoak. She is also good friends with Professor Martin Stein. She was a former love interest of Hunter Zolomon who was masquerading as Jay Garrick.

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. After being taken over by her rising anger while using meta-human powers she briefly started going by her doppelgänger's name Killer Frost.

Early life
Based on what her Earth-2 counterpart would tell her in adult life about her version of the Snow family, it's implied that Caitlin has/had a brother named Charlie she is isn't aware of. 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 her 1 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.

Return of Killer Frost
Whether as a result of Flashpoint or not, Caitlin developed cryokinesis meta-human powers similar 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 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. 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 in to confront her, and Caitlin 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 web cam and told her that her results proved unfruitful, and 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 computer, 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 HR 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 he to reveal the truth about her powers to the team.

Caitlin was forced to use her powers to save Barry from Savitar; unfortunately, she ended up dominated by her worry and anger, turning into a new 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 CCPD 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 police 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, Killer Frost turned against Barry in anger, and despite him saving her from the SCIS, 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 Caitlin 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 Caitlin declared herself as Killer Frost and attacked Cisco. Barry then arrived on the scene and knocked Caitlin 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, Caitlin attempted in 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 who yelled at him, blaming Barry for everything bad that happened to the team after his "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 put power dampeners on herself, assisting the team in returning Wally to normal (albeit now with Super-Speed).

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.

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.

Possible futures
In a possible future shown by Cisco's vision, and to Savitar's Speed Cult by Savitar himself, Caitlin had fully assumed the mantle of Killer Frost and would be described as incredibly powerful by one of the Acolytes.

Personality
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 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.

Caitlin's defining trait is her short-tempered compassionate side, as when checking and treating members of the team who are hurt, she often scolds them for endangering their lives, especially Barry.

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 acute stress reaction, much like her lover due to his frightening behavior, questioning if she still has her sanity. Since the correction of the Flashpoint reality Barry created Caitlin has begun displaying powers of cryokinesis like her Earth-2 counterpart. 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.

Killer Frost
After her powers from the particle accelerator manifested, Caitlin was slowly taken over by her abilities resulting in her personality deteriorating into a vindictive, angry person the more she used her abilities. As Killer Frost, she mocked Barry by mentioning his most horrible failures including his mother, father, Eddie and Ronnie, as well as revealing to Cisco that his brother, Dante was alive in the pre-Flashpoint timeline. She also mocked Cisco by calling him pathetic for feeling sorry that he had to hurt her to save Barry. She also openly blames Barry for what's happened to her and admits that she feels broken. She also nearly killed Julian and one of Alchemy's Acolytes, however she was still unable to kill Barry which made her revert to her normal persona and she became horrified at what she almost did.

Powers
"My name is Killer Frost."

- Killer Frost


 * Meta-human physiology: By unknown means, when Caitlin started to develop powers of her Earth Two counterpart, this altered her DNA and supercharged her cells, augmenting her physiology into beyond peak human condition.
 * Energy absorption: After Caitlin was caught in the particle accelerator's explosion's shock-wave, she gained the power to absorb heat energy around her.
 * Cryokinesis: Caitlin has begun to manifest signs of this ability, producing icy mist from her hand as well as freeze objects to temperatures well below negative 370 degrees. However, Caitlin's has very little control over her powers and shows physical changes because of them, such as her hair turning white like Killer Frost's and lips turning blue. Caitlin's condition is progressive, meaning that her powers will become ever more permanent as she continues to use them. As she has continued to channel her powers, she has shown physical changes. One of which is her eyes glowing a pale whitish-blue during moments of heightened emotion. The physical changes become more prominent as she makes use of her abilities, though will recede if she goes long enough without using them, such as her hair going from white back to its original chestnut brown. Caitlin can also create solid structures made of ice with ease, making an icicle to kill Barry with seemingly no effort (Although she didn't go through with it).
 * Freezing breath: Caitlin is able to create a fog with her breath. She used this ability when she was trying to know the whereabouts of Alchemy by threatening one of his followers and she created a fog around the room in order to escape.

Abilities

 * High-level intellect: Caitlin is very intelligent, as evidenced by the crucial role she plays in Team Flash, she along with Cisco Ramon were able to create a cure for Mirakuru.
 * 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 Eobard Thawne after he was brutally beaten up by his Reverse-Flash speed mirage.
 * Trained neurosurgeon: Caitlin once mentioned that she knows how to perform a lobotomy, a procedure that requires both training and skill in the field of neurosurgery.

Weaknesses

 * Power-induced rage: As Caitlin uses her powers more, it is shown that her eyes glow a pale whitish-blue. She is a very different person at this point, seemingly filled with rage and quite cold. It is difficult to calm her down, as her mother was just barely able to stop her from killing her research assistant who tried to stop her from leaving.
 * 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 Cait accidentally freezing her desktop monitor. Recently, Caitlin has seemingly begun to use her powers (in small doses) with no adverse affect.