~ Crystal Frost/Killer Frost's last words in Suicide Squad: Hell to Pay
(Firestorm: Hey, Frosty.) Hey, Stormy
~ Killer Frost and Firestorm when she captive by Mr. Freeze
Killer Frost is the identity of a criminally insane supervillainess from DC Comics, who (as her name implies) has control over the cold - she is a mass murderer and very dangerous (even by supervillain standards): as well as appearing in comic books she has been involved in the DC animated universe and video-games such as Justice League Heroes.
Crystal Frost was the first, Louise Lincoln (voiced throughout the DC animated universe and other projects by Jennifer Hale) was the second, and Caitlin Snow was the third.
Crystal Frost first appeared in Firestorm #3 (June 1978). While Crystal Frost was studying to be a scientist in Hudson University, she fell in love with her teacher, Martin Stein. While working on a project in the Arctic, Frost was upset to learn that Stein did not reciprocate her feelings. Frost accidentally locked herself in a thermafrost chamber, but somehow survived. She was transformed in a way that she was able to absorb heat from a living being and project cold and ice. Calling herself Killer Frost, she began her murderous crusade against men and clashed with Firestorm on many occasions. Frost eventually died after she absorbed too much energy from Firestorm.
Hall of Justice memorial
Crystal has been identified as one of the deceased entombed below the Hall of Justice. Her body was reanimated as a Black Lantern.
Dr. Louise Lincoln first appeared in Firestorm (Volume 2) # 21 (1984). She was a colleague and friend to Crystal Frost. After her friend died, she decided to repeat the experiment as a last respect to her former mentor, and became the new Killer Frost. She became just as ruthless as her predecessor and began her own personal vendetta against Firestorm, who she blamed for Frost's death. She briefly served as a member of the Suicide Squad and sold her soul to Neron for more power.
During the Underworld Unleashed event, Killer Frost attacked Hawaii, freezing part of the islands before being stopped by Superboy and Knockout.
Killer Frost was later freed by Effigy and the two had a brief flirtatious partnership before she was apprehended by Green Lantern.
Killer Frost was one of many mega-villains seeking to earn a $1 billion reward offered by President Lex Luthor to sanction Superman and Batman, whom he considered treasonous. She teamed with Mister Freeze, Icicle, and Captain Cold in an attempt to ambush the two heroes, but all four were defeated. It was later discover that this ice-themed team of villains was being mind controlled by Gorilla Grodd.
Doctor Light (Arthur Light) hired Killer Frost and Mirror Master to attack Green Arrow and Black Lightning at a hospital in Chicago, Illinois where Kimiyo Hoshi was being held. Green Arrow stopped Killer Frost by firing an arrow filled with Greek fire into her thigh. Unable to absorb the heat from the arrow, she was soundly defeated by Green Arrow.
One Year Later and Countdown
Killer Frost was later seen in the Justice League of America Wedding Special, battling the new Firestorm, until Lex Luthor, Joker and Cheetah arrived, subdued Firestorm, and invited her to join the new Injustice League.
In other media
The Flash And Arrow
Dr. Caitlin Snow appears as a supporting protagonist in the TV series The Flash and a guest star in Arrow, played by Danielle Panabaker. She is featured as a scientist at S.T.A.R. Labs and employee of "Harrison Wells", as well as girlfriend of Ronnie Raymond/Firestorm. In the Season 1 finale of The Flash "Fast Enough", she marries Ronnie. Later, when Barry is running through the Particle Accelerator to go back in time, a brief shot of Snow in an ice-like dress is seen, suggesting that she would become the character.
In Season 2, while Snow herself did not become Killer Frost, her Earth Two counterpart had become the character, being a minion of Zoom and appearing in the episodes "Welcome to Earth-2" and "Escape from Earth-2". She is the wife of Ronnie Raymond from Earth-2, who is known as Deathstorm. After Zoom kills him, Snow is convinced by Cisco (Earth-1) and Barry Allen (Earth-2) to help them rescue the Flash/Barry Allen (Earth-1) from Zoom's hideout. After Cisco, Barry, Wells (Earth-2) and Jesse Quick left for Earth-1, Cisco started fearing that Snow from Earth-1 was starting to become like her. In the episode "Back to Normal", she was shown to be imprisoned by Zoom in his lair. She tricks the then-trapped Earth-1 Caitlin into helping her escape; when she was about to kill her unpowered self by hurling an icicle at her, Zoom arrived, grabbed the icicle and stabbed Frost with it, killing her.
In Season 3, during the briefly-displayed Flashpoint timeline, Caitlin served as an ophthalmologist. After Barry restores the timeline from Flashpoint, the world had been affected by small, but important changes, such as Cisco's brother Dante being killed by a drunk driver and Iris and Joe West having a strained relationship. Barry seemed to think that Caitlin was the least-affected by the timeline alteration; however, she had actually become a meta-human with the same powers as her Earth-2 counterpart, fearing that she would be transforming into her. She goes to her scientist mother in an attempt to understand what was happening to her, but found out that the more she used her powers, the more she'd be like Killer Frost. Her powers started going out of control after that until the episode "Killer Frost", in which she takes the same appearance as her Earth-2 counterpart and tried finding her way to Doctor Alchemy, who possessed a stone (called the Philosopher's Stone) that could both grant meta-human powers to people and take them away (never seen on-screen).
Barry and Cisco manage to stop her, but by the time they do, she has already kidnapped CSI Julian Albert (unaware that he is Alchemy) and almost killed one of Alchemy's disciples. Later, Barry travels just months into the future (May 2017) to learn about the future and hopefully prevent Alchemy's master Savitar from killing Iris West. He sees a TV news headline stating "Killer Frost still at large", which worried Caitlin.
Later, she reveals to the team that she broke off a piece of the Philosopher's Stone before it got thrown into the Speed Force, saying that she did it to determine how to get rid of her powers. In the episode "Abra Kadabra", in order to save her life from an injury, Julian removes her power-dampening necklace, turning her into Killer Frost and prompting her to storm out of S.T.A.R. Labs. In the episode "Once and Future Flash", Barry travels ahead of time to 2024, by which point Iris has already died and Caitlin is locked away at S.T.A.R. Labs for assisting Savitar in his scheme.
She says she knows who he is, but refuses to tell anyone. At the end of the episode, present-day Killer Frost meets Savitar, who takes off his armor in font of her and reveals his identity; Barry's time remnant. She continues assisting him in various ways until the finale episode "Finish Line", when she turns on him and allows him to die. After H.R. Wells' funeral (he was killed by Savitar), Caitlin is spotted by the team, but she doesn't fight them. Instead, she gives back her power-dampening necklace and says that she needs to go figure out what she's supposed to do with herself now that she is neither Caitlin nor Killer Frost. She leaves after that.
Powers and Abilities
Thermokinetic Cryokinesis: Like her predecessor, Killer Frost has the ability to generate extreme temperatures of cold from her body. By absorbing heat from the atmosphere, she can freeze molecules of moisture that hang in the air, creating a variety of effects. Primarily this is used to freeze others in place or to create a sheen of ice over an intended target. Killer Frost can also use her powers to summon gusts of super-cold air, with which she uses to hurl frozen objects (usually ice daggers) at specified targets. She often uses hand gestures while doing this to make it appear as if she can project ice directly from her fingertips. This is not necessary however, and is done mostly for theatrical effect.
Minor Heat-Resistance: Contrary to others who share her power set, heat does little damage to Killer Frost. In fact, heat is essential to her continued existence. Attacking Killer Frost with a heat based-weapon only serves to strengthen her.
Hypothermia Kiss: A trademark tactic common to both Killer Frost characters is to create a block of ice around a target's feet securing them into place, and then kiss them, absorbing all of the heat from their body until they freeze to death.
A slow cold death for.
~ Killer Frost in Injustice.
Let me tell you something about pity, Warden. Pity kills the soul. Pity can break your heart.
~ Killer Frost.
Of course you can get close, little man. But if you get close to Killer Frost...you have to pay the price!