- For other uses of "Killer Frost", see Killer Frost (disambiguation).
|Occupation|| Bioengineer at S.T.A.R. Labs|
Member of Team Flash (in secret)
Henchwoman of Amunet Black (formerly)
Co-Leader of the Cult of Savitar (formerly)
Scientist at Mercury Labs (formerly)
Ophthalmologist (Flashpoint timeline)
|Family|| Unnamed (father)|
Ronnie Raymond (husband; deceased)
|Alter ego||Killer Frost|
Dr. Caitlin "Cait" Snow 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, before discovering his true 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 and Felicity Smoak. 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.