Killer Frost

Crystal Frost was the first incarnation, first appearing in Firestorm #3 (June 1978).^[2] She is an aspiring scientist at Hudson University who possesses unreciprocated feelings for her teacher Martin Stein. After accidentally locking herself in a thermafrost chamber, Frost gains cryokinetic abilities and becomes a supervillain and enemy of Firestorm.^[3] Frost is later killed after absorbing excessive energy from Firestorm.^[4] Years later, she is resurrected as a Black Lantern in Blackest Night.^[5][6]

Louise Lincoln is the second incarnation of Killer Frost; she first appeared in Firestorm (vol. 2) #21 (March 1984) and used the "Killer Frost" name in Firestorm (vol. 2) #34 (April 1985).^[7] Lincoln is a colleague and friend of Crystal Frost who succeeds her as Killer Frost following her death.

In subsequent appearances, Lincoln joins the Suicide Squad, sells her soul to Neron to enhance her powers, and briefly enters a relationship with Effigy. She is among the villains who seek to claim Lex Luthor's bounty on Batman and Superman during the Superman/Batman "Public Enemies" arc.^{[8][9][10][11]}

Around this time, Lincoln is diagnosed with cancer and tricks Jason Rusch, the new Firestorm, into curing her. With her health and powers restored, Killer Frost went on a rampage, only to be defeated when Jason undoes his actions.^[12]

In One Year Later, Frost allies with Mr. Freeze. However, she reveals that she had been using Freeze as a pawn and had no interest in him.^[13]

In Salvation Run, Frost is among the villains sent to another planet. She later joins Libra's Secret Society of Super Villains and is among the villains sent to retrieve the Get Out of Hell Free card from the Secret Six.^[14][15] During the Doomsday Clock event, Frost supports the "Superman Theory" and claims that the U.S. government gave Captain Atom, Firehawk, Moonbow, and Typhoon their powers.^[16][17]

The third incarnation of Killer Frost is Caitlin Snow, introduced in The New 52 continuity reboot.^[18] She is a scientist who gains powers after H.I.V.E. agents attempt to kill her with a thermodynamic engine. In subsequent appearances, Snow seeks help from Firestorm and Martin Stein to cure her condition and joins the Suicide Squad and Justice League.^[19][20][21]

All versions have shown the ability to absorb heat from external sources and transmute it into waves of cold. Using these powers, Killer Frost can create an ice-sheen across her entire body that grants her increased durability, cause intense blizzards that can instantly freeze the target and generate objects composed completely of ice, such as projectiles in the form of ice shards and defensive walls or shields. She can also instantly freeze animate matter through physical contact and is unable to touch a normal person without freezing them. However, if someone has a power or ability that negates the natural waves of freezing cold that come from her body, she can touch them without anything happening, as seen when she kisses Firestorm.

Her weakness is the need to absorb external heat sources to generate ice: although heat-based weapons such as flamethrowers only make her stronger, she can be imprisoned in cold surroundings such as being locked in a refrigeration truck or buried under a mountain of snow. The Caitlin Snow version of Killer Frost is constantly plagued by a hunger for heat, which can only be sated by absorbing the heat from a living being, a process which inevitably kills the victim. However, in recent stories she seems to have finally gotten it under control by only absorbing a tiny amount of heat from every person she touches, sparing them and leaving them otherwise unharmed. The Caitlin Snow and Louise Lincoln versions of the character have, albeit inconsistently, demonstrated the ability to fly, either by riding Arctic winds or through an unknown manner of self-propulsion.

While the exact limits of her abilities have yet to be established, how much power Frost can channel at once seems to depend on how much heat she has absorbed and stored in her body. For example, when she absorbed all the heat from Superman (whose body is supercharged by yellow solar energy) during a stand-off between the Justice League and the Suicide Squad, she was able to flash-freeze the entire League in a single blast.

It also seems that using up all the heat energy she has stored can put Frost's life in danger. If she does not feed in time, she even risks dying of what she calls "starvation".

The Caitlin Snow version also boasts a genius-level intellect, being S.T.A.R. Labs' youngest and brightest scientist prior to her transformation. She could solve complex equations easily, operate heavy energy generating machinery and appeared particularly skilled in the field of physics and research about energy. She once managed to create an ice prism with her powers that converted Superman's heat vision into a bright burst of sunlight to defeat Eclipso.

Several adaptations of the villain have also depicted the Crystal Frost and Louise Lincoln incarnations as having basic skills in melee combat which they use in conjunction with their powers as well as impressive agility, being able to perform maneuvers such as leaps or cartwheels with ease.

An alternate universe variant of Killer Frost appears in DC Comics Bombshells.^[22] This version is Louise L'inconnue, a servant of Hugo Strange who is of French and German descent and gained her powers after her mother was killed and she was left to die in a well.^[23]

• The Louise Lincoln incarnation of Killer Frost appears in series set in the DC Animated Universe (DCAU), voiced by Jennifer Hale.^[24] This version is motivated by a base desire to kill people and does not seem to care who she serves so long as she is afforded the opportunity to kill.
  • She first appears in the Justice League two-part episode "Secret Society" as a member of Gorilla Grodd's eponymous team, though they are eventually defeated by the Justice League.
  • Killer Frost appears in Justice League Unlimited, having rejoined Grodd's Society as of the episode "I Am Legion". Prior to and during the episodes "Alive!" and "Destroyer", Lex Luthor takes control of the Society, but Grodd mounts a mutiny. Killer Frost initially sides with the latter before defecting to the former, freezing Grodd's remaining loyalists in the process. After Darkseid attacks and kills most of the Society, Luthor, Killer Frost, and the survivors join forces with the Justice League to defeat him and thwart his invasion of Earth.
• An amalgamated incarnation of Killer Frost appears in the teaser for the Batman: The Brave and the Bold episode "Darkseid Descending!", voiced again by Jennifer Hale. This version is identified as Louise Lincoln, resembles Crystal Frost, and is Ronnie Raymond's vengeful ex-girlfriend.
• The Crystal Frost incarnation of Killer Frost appears in Young Justice, voiced by Sarah Shahi.^[24]
• The Caitlin Snow incarnation of Killer Frost appears in the Justice League Action episode "Freezer Burn", voiced by Mena Suvari.^[24] This version gained her powers during a freak accident involving "thermafrost" and is a fan of Mr. Freeze.
• An unidentified incarnation of Killer Frost makes non-speaking cameo appearances in Harley Quinn. This version's appearance resembles her counterpart from Batman: Assault on Arkham.

Danielle Panabaker portrays Dr. Caitlin Snow in media set in the Arrowverse. Following initial guest appearances in Arrow and primarily appearing in The Flash, this version is a member of a Central City-based S.T.A.R. Labs team alongside Cisco Ramon / Vibe and Harrison Wells, which supports Barry Allen / Flash.

In the first season, she struggles with her fiancé Ronnie Raymond's apparent death following S.T.A.R. Labs particle accelerator exploding and creating various metahumans before later discovering Raymond survived as part of Firestorm. Caitlin and Raymond later marry, but he sacrifices himself to help the Flash close a singularity that opened over Central City. During the second season, Caitlin grieves for Raymond, but grows closer to Hunter Zolomon while he was disguised as Jay Garrick. When Zolomon reveals he has a condition that limits the use of his super-speed, Caitlin develops the Velocity serum to save his life. However, she and Team Flash soon discover Zolomon's true identity before he kidnaps her and takes her to Earth-2, where she meets her evil Earth-2 doppelganger, Killer Frost. Following this encounter, Caitlin begins to fear whether she has a capacity for evil as well.

Due to Allen altering the timeline while creating and undoing the "Flashpoint" timeline in the third season, Caitlin developed cryokinetic abilities and an alternate, villainous personality, both of which she attempts to hide from her friends.^[25][26][27] Additionally, she develops a relationship with Julian Albert, is advised by her mother, Dr. Carla Tannhauser, to not use her powers or her transformations will become irreversible, and dons a power-suppressing necklace. However, Catlin's abilities fully manifest after she sustains lethal injuries and Albert removes her necklace so she can use her healing abilities to save herself, triggering her transformation into Killer Frost. Joining Savitar as his enforcer, she battles Team Flash until Albert gives her a cure he developed. She subsequently betrays Savitar and helps her friends defeat him before leaving to rediscover herself.

In the fourth season, Caitlin and Killer Frost develop a "Jekyll and Hyde"-esque relationship while the former works to reconcile her dual personalities,^[28][29] giving herself the ability to switch between her two personas at will. Furthermore, Killer Frost begins to show a more heroic side and agrees to use her powers to help Team Flash. Later in the season, Caitlin discovers her powers and Killer Frost originated during her childhood and that she suppressed the memories.

In the fifth season, Caitlin discovers further that her father, Thomas Snow, experimented on her and himself in an attempt to cure their ALS genes, resulting in them both developing alternate personalities with cryokinetic powers. After he becomes Icicle, Caitlin and Killer Frost work together to save Thomas from his evil persona, with Killer Frost renaming herself "Frost".

In the sixth season, Caitlin experiments with giving Frost more time with their shared body and allowing her to live her own life. In the seventh season, they are separated after being exposed to Mirror Monarch's rays and decide to live separate lives as twin sisters.

In the eighth season, Frost transforms into Hellfrost and sacrifices herself to defeat Deathstorm. Having secretly taken a hair sample from Frost, Caitlin tries to resurrect her with Chillblaine's help by entering the Consciousness Resurrection Chamber, but the machine malfunctions, causing a new individual named Khione (also portrayed by Panabaker) to emerge in the ninth season.^[30] Eventually, Khione becomes a nature goddess and returns Caitlin's body to her.

Caitlin also appears in the animated series Freedom Fighters: The Ray, with Panabaker reprising the role.^[24]

• The Louise Lincoln incarnation of Killer Frost appears in Superman/Batman: Public Enemies, voiced again by an uncredited Jennifer Hale. This version is a member of the "Cold Warriors".
• The Louise Lincoln incarnation of Killer Frost appears in Batman: Assault on Arkham, voiced again by Jennifer Hale.^[24][31] She is recruited by Amanda Waller to join the Suicide Squad and break into Arkham Asylum to retrieve data stolen by the Riddler, though Waller secretly assigns Killer Frost to kill him. Over the course of the mission, Killer Frost forms a friendship with King Shark while the squad learns the Riddler can defuse the bombs Waller implanted in their necks to keep them in line. After they successfully do so, Killer Frost attempts to escape, only to be killed by Bane amidst a mass breakout.
• Caitlin Snow / Frost appears in DC Super Hero Girls: Hero of the Year, voiced by Danica McKellar.^[24]
• Caitlin Snow / Frost appears in DC Super Hero Girls: Intergalactic Games, voiced again by Danica McKellar.^[24]
• The Crystal Frost incarnation of Killer Frost appears in Suicide Squad: Hell to Pay, voiced by Kristin Bauer van Straten.^[32][24] This version is a "tough girl" who killed her abusive parents after her powers manifested when she was young. She is recruited into Amanda Waller's Suicide Squad to retrieve a "Get Out of Hell Free" card, but is swayed by Professor Zoom into helping him get the card for himself. Killer Frost betrays Zoom, but is attacked by Copperhead and killed by Waller via Copperhead's nano-bomb.
• Caitlin Snow / Frost appears in Lego DC Super Hero Girls: Super-Villain High, voiced again by Danica McKellar.^[24]
• Caitlin Snow / Frost appears in DC Super Hero Girls: Legends of Atlantis, voiced again by Danica McKellar.^[24]
• The Louise Lincoln incarnation of Killer Frost makes a non-speaking cameo appearance in Injustice.^[24]

• The Louise Lincoln incarnation of Killer Frost appears as a playable character in Justice League Heroes, voiced by Nika Futterman.
• The Louise Lincoln incarnation of Killer Frost appears as a boss in DC Universe Online, voiced by Christina J. Moore.^[24]
• The Louise Lincoln incarnation of Killer Frost appears in Injustice: Gods Among Us, voiced again by Jennifer Hale. In an alternate reality, she sports Caitlin Snow's attire and serves as a member of Superman's Regime.
• The Louise Lincoln incarnation of Killer Frost appears as a character summon in Scribblenauts Unmasked: A DC Comics Adventure.^[33]
• The Crystal Frost incarnation of Killer Frost appears as a boss in Young Justice: Legacy, voiced by Vanessa Marshall.^[24]

• The Louise Lincoln incarnation of Killer Frost appears as an unlockable character in the portable version of Lego Batman 2: DC Super Heroes.
• The Caitlin Snow incarnation of Killer Frost appears as a downloadable character in Lego Batman 3: Beyond Gotham.
• The Caitlin Snow incarnation of Killer Frost appears in Lego DC Super-Villains, voiced by Jennifer Hale.^[34] This version is a member of the Legion of Doom.

• The Crystal Frost incarnation of Killer Frost appears in Justice League Adventures #12 as a member of the Cold Warriors.^[35]
• The DCAU incarnation of Louise Lincoln / Killer Frost appears in issue #21 of the Justice League Unlimited tie-in comic book, in which she enters a relationship with Heat Wave.^[36]
• An unidentified incarnation of Killer Frost appears in DC Super Friends #16 as a member of the "Ice Pack".^[37]
• The Injustice incarnation of Louise Lincoln / Killer Frost appears in the Injustice: Gods Among Us prequel comic.
• Caitlin Snow / Frost appears in DC Super Hero Girls, voiced by Danica McKellar.^[24] This version is a hero, student at Super Hero High, and roommate of Lady Shiva, Miss Martian, and Star Sapphire.