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For other uses of "Killer Frost", see Killer Frost (disambiguation).

"If you knew me at all, you would know that I hate the name Caitlin. I'm Killer Frost!"
—Caitlin Snow to Barry Allen[src]

Caitlin Snow (died April 26, 2016), also known as Killer Frost, was a meta-human criminal from Earth-2 who gained powers of cryokinesis from the S.T.A.R. Labs particle accelerator explosion. Caitlin was the wife of the late Ronnie Raymond, the estranged daughter of an unnamed woman, and the sister of the late Charlie Snow. She was also a former enforcer of Zoom's meta-human group and a brief reluctant ally of Team Flash.


Early life

Caitlin Snow had a brother named Charlie who eventually died, leaving her mother "cold". She later went to medical school, but rarely studied and around 2013, Caitlin flunked out and had to move back in with her mother. Not long after, she was affected by Harrison Wells' S.T.A.R. Labs particle accelerator, giving her cryokinetic abilities.[1]

Since then, Caitlin cut off all ties to her past life and began calling herself "Killer Frost", refusing to use her real name; even so much as hearing it made her angry. At one point in her life, Caitlin met and married Ronnie Raymond, a fellow meta-human criminal with pyrokinetic abilities. The two of them were recruited into the villainous speedster Zoom's army and acted as his enforcers in Central City under the latter's right-hand man, Francisco Ramon/Reverb.[2] Caitlin was also associated with Laurel Lance/Black Siren, Zoom's top lieutenant.[3]

The arrival of Earth-1 Flash

Caitlin and Ronnie kiss.

After Reverb sensed that his doppelgänger, along with other Earth-1 residents, had arrived on Earth-2, Caitlin and Ronnie searched for them. The two broke into Jitterbugs and interrogated its patrons. Suddenly, Detective Iris West-Allen pulled out her gun and attempted to arrest them. As Caitlin moved to attack her, Earth-1 Barry Allen (disguised as his Earth-2 counterpart) attempted to reason with her, calling her Caitlin, to which she replied she no longer went by that name. Caitlin then fired icicles at Barry and Iris, who used a table as a shield. After Ronnie critically injured Joseph West, Caitlin and Ronnie were brought outside by Barry while Iris was distracted by her father, revealing he was the Flash. Caitlin attempted to kill the Flash with icicles but failed and told her husband to do so, becoming turned on while watching their battle. The Flash used a helmet from a statue of "Jay Garrick" to redirect one of Ronnie's blasts towards Caitlin, injuring her. She was then taken away and tended to by Ronnie.

Killer Frost and Deathstorm confront Iris, Lawton and Vibe.

Later, Caitlin and Ronnie were approached by Iris, Detective Floyd Lawton, and Cisco Ramon/Vibe, Reverb's doppelgänger, but Caitlin forced them to stand down and drop their weapons. Iris expressed anger at the duo for her father's death, but they were unrepentant. When Reverb revealed himself, Caitlin was annoyed that he tried to get Cisco to join him and suggested they should just turn the intruders over to Zoom but Reverb silenced her with a threat. Suddenly, the Flash appeared and incapacitated Caitlin, Ronnie, and Reverb. Iris wounded Caitlin with the Anti-Killer Frost Derringer, much to Ronnie's fury. Reverb and Ronnie eventually overpowered the Flash and began continuously hitting him. Caitlin urged them to cease fire, warning that Zoom wanted the Flash unharmed. Just then, Zoom arrived and quickly killed Ronnie and Reverb, much to Caitlin's horror. Zoom then grabbed Caitlin by the throat but spared her, stating he was happy to see that she knew her place. After Zoom sped off with the Flash, Caitlin ran toward her husband's body but soon took off in despair.[2]

Caitlin is held at gunpoint by Cisco.

Caitlin fled into the Woodlands to mourn Ronnie's death. The next day, she was approached by Iris, Harry, Cisco, and Earth-2 Barry, demanding to know where Zoom was in order to find the Flash and Harry's daughter, Jesse Wells. Caitlin refused to say anything and instead tried to kill them and bring them to Zoom. Cisco eventually held her at gunpoint with the Derringer and Caitlin surrendered, but still refused to tell them where Zoom was. Cisco tried to reason with her, telling Caitlin of her Earth-1 counterpart and how distraught she was when her Ronnie died too. Upon hearing this, Caitlin was seemingly convinced to aid them and took the group to Zoom's lair at Ascension Cliffs, using her powers to create a walkway.

Caitlin attacks Zoom.

With some more persuasion from Cisco, Caitlin freed Jesse but was unable to free the Flash since her powers couldn't penetrate the carbine glass imprisoning him, though he eventually managed to phase out on his own. Zoom then showed up, revealing Caitlin secretly called him. He attempted to kill the group, but Caitlin suddenly turned on Zoom for what happened to Ronnie and blasted the villainous speedster with her ice powers, holding him down long enough for everyone else to escape.[4] Instead of being killed for her betrayal, Caitlin was imprisoned in Barry's carbine cell.[1]


Caitlin meets her doppelgänger.

After a couple months of imprisonment, Caitlin grew annoyed by her fellow inmate with an iron mask and wasn't sure why she was even still alive. It wasn't until Zoom brought her doppelgänger that Caitlin realized she was spared because she is the Earth-2 version of the woman Zoom loves, and began plotting her escape. However, Caitlin always intended on killing her doppelgänger, because of both revenge on Zoom for Ronnie's death and the fact that he wouldn't need her anymore.

When Earth-1 Caitlin met her, Caitlin introduced herself and proposed a deal: if Earth-1 Caitlin freed her, she will help the latter get home to her Earth. While working, both Caitlins talked of their very different lives, but found common ground in their shared dislike for their respective mothers. Earth-1 Caitlin used electrical cables to heat up and weaken the carbine's molecular structure enough for her to smash the glass, allowing Caitlin to escape. As Earth-1 Caitlin wondered what to do about the man in the mask, Caitlin tried to kill her with an icy blast.

Zoom kills Caitlin.

Earth-1 Caitlin protested that they had a deal but Caitlin simply scoffed at her naiveté. When her doppelgänger tried to flee, Caitlin used her powers to create a sheet of ice, causing the former to slip and fall. She revealed why Zoom kept her alive, which wasn't necessary now that he had Earth-1 Caitlin. As Caitlin was about kill her Earth-1 counterpart with an icicle projectile, Zoom intervened and took it from mid-air. He brutally stabbed Caitlin in the stomach with the icicle, confirming that he doesn't need her anymore. Zoom dropped Caitlin's body to the ground, leaving her to die.[1]

Possible future

Caitlin using her powers in a possible future.

In a possible future, Caitlin used her powers whilst wearing a different, more revealing Killer Frost suit. Barry caught a glimpse of this while traveling through the Speed Force.[5]


In order to keep Black Siren occupied, Earth-1 Caitlin and Cisco impersonated their Earth-2 doppelgängers and tried to convince her to join them, though Black Siren soon saw through the ruse.[3]

Earth-2 Caitlin's death was avenged when Barry Allen helped to ensure that Zoom was captured by Time Wraiths and was subsequently turned into Black Flash, doomed to serve the Speed Force as its enforcer.[6] Earth-1 Caitlin (as her own version of Killer Frost) later killed Zoom (who had become Black Flash) when the latter tried to kill Savitar.[7]

Following the creation of the Flashpoint timeline and its eventual undoing by the Reverse-Flash, Earth-1 Caitlin's personal history changed significantly, with her developing freezing powers as a child, far before the particle accelerator explosion, and her split personality of Killer Frost around the same time. It was later discovered that Earth-1 Caitlin developed both her powers and Killer Frost side due to experiments performed on her by her father Thomas Snow. Eventually, Earth-1 Caitlin was able to come to terms with her Killer Frost side, allowing them to coexist.


Unlike her Earth-1 counterpart, who is compassionate and loving, Caitlin was cold, cruel, sadistic, ruthless, arrogant, and immoral. She took pleasure in murdering innocent people and terrorizing Central City as Zoom's enforcer without a shred of remorse. Caitlin had a dry, mocking, and sadistic sense of humor, which she often expressed against her targets, willing to play mind games with her victims and make conversation before hurting/killing them.

The only person Caitlin truly cared for was her husband, Ronnie Raymond; the two were deeply in love and always protected each other. Apropos, Caitlin had a fairly uninhibited personality, being public with her affections for Ronnie, even expressing how she gets turned on when witnessing him in battle. Caitlin seems to be slightly vain as well, taking great pride in her looks and wearing form-fitting clothing to show off her figure; she also teased her Earth-1 doppelgänger over the latter's more modest clothing.

Caitlin's attitude and criminal nature is implied to have partially stemmed from her difficult past, with the death of her brother and subsequent estrangement from her mother.[1] This was reflected in how Caitlin only refers to herself as Killer Frost, hating even the sound of her real name.[2]

Underneath her arrogance, Caitlin was openly terrified of Zoom; unlike Ronnie and Francisco Ramon, she knew better than to disobey his orders, knowing the evil speedster would kill her for trying to harm the Flash.

After Zoom murdered Ronnie, Caitlin was devastated and heartbroken, desiring revenge on Zoom. She was willing to briefly ally with Team Flash to help free the Flash and Jesse Wells, the speedster's prisoners, regardless of the potential risks. Caitlin was also seemingly empathetic upon learning her Earth-1 doppelgänger also lost her Ronnie. However, her desire for revenge soon grew beyond reason; Caitlin tried to murder her doppelgänger, who Zoom loved, in an attempt to inflict the same pain on the speedster despite the fact that Earth-1 Caitlin helped the former escape from her cell.

Powers and abilities


  • Meta-human physiology: After Caitlin was struck by the energy of the Particle Accelerator explosion on Earth-2, this altered her DNA and supercharged her cells, augmenting her physiology to properly access her powers. The physical alterations that accompanied her meta-abilities were pale skin, white hair, and blue eyes.
    • Thermokinetic cryokinesis: By absorbing thermal energy from molecules to create gelid surroundings, Caitlin can generate dangerously low temperatures from her body, letting her freeze virtually anything. She can thus create sheets of ice, or shoot spearlike icicles at opponents. Caitlin often gestures when using her powers, but can also freeze things by touching them (e.g. she once froze a man's entire body through a kiss).[2]
    • Cold immunity: An added benefit to her powers, Caitlin's cells can withstand sub-zero temperatures.
    • Heat immunity: Caitlin's powers allow her to easily withstand intense heat temperatures. She was able to kiss and touch her husband, Ronnie Raymond, while he was Deathstorm.[2]


  • High-level intellect/Expert tactician: As an enforcer for Zoom, Caitlin was very intelligent and a capable tactician.
    • Medical knowledge: Despite failing medical school, Caitlin was shown to have some knowledge in medicine. For example, she deduced that heating carbine with electricity would weaken its molecular structure.[1]
    • Expert of deception/Manipulator: Caitlin was able to deceive Team Flash and her Earth-1 counterpart into believing she was on their side and even manipulated the latter into helping her escape from Zoom's lair.
  • Expert hand-to-hand combatant: Caitlin displayed an expertise in unarmed combat when she fended off a gang of bank robbers[2] and swiftly disarmed Iris West-Allen of her gun.[4]
    • Expert markswoman: Caitlin was a proficient markswoman, both with guns and her powers, as she fires icicle projectiles to attack her opponents.
  • Intimidation: With her dangerous powers and cold, sadistic nature, Caitlin commands an intimidating presence, being able to frighten people with just her appearance due to her reputation as an enforcer for Zoom.


  • Carbine: Caitlin's cryokinesis had no effect on this compound.[2]
  • Limited control: Caitlin implied she could not control her powers upon contact with others, thus limiting her to only being able to touch people with extreme body temperatures, such as her late husband.[2]


  • Killer Frost suit: Caitlin wore a suit as her villainous alter-ego, Killer Frost. The suit consists of black and blue leather clothing to match Caitlin's cold personality and powers.


The Flash

Season 1

Season 2

Season 3

The Chronicles of Cisco


Promotional images

The Flash

Season 2


  • Caitlin and Ronnie's couple song is "My Funny Valentine".[2]
  • Unlike Earth-1 Caitlin Snow, Caitlin is more willing to show off her body. However, after Earth-1 Caitlin got powers, her Killer Frost side changed clothes in front of Iris, Felicity, and Cecile,[8] implying that it's only the Killer Frost persona in both versions of Caitlin who doesn't like to dress modestly.
  • Apparently, Caitlin Snow doesn't exist on Supergirl's Earth.[9] However, as shown by Jay Garrick being Henry Allen from Earth-3, same versions of people do not necessarily have the same name.
  • Caitlin shares some similarities with Earth-2 Laurel Lance; both women turned to a life of crime upon gaining powers due to past traumas over deaths in the family. They both worked for Zoom and were in love with the same men of their Earth-1 doppelgängers were. They have similar snarky and sadistic natures, willing to attack and mock the Earth-1 versions of themselves.
  • Caitlin is the first person and dopplegänger from a different Earth to appear across all Arrowverse shows and only to appear in the first season of The Flash.

Behind the scenes

  • Killer Frost is an alias used by three different female meta-human super-villains, all of whom were enemies of Firestorm in the main DC Comics continuity.
    • In the pre-Crisis on Infinite Earths timeline, Crystal Frost (introduced in Firestorm: The Nuclear Man #3, in June 1978) was a college student in love with Professor Martin Stein. She became the first Killer Frost after a freak accident which imbued her with the power to absorb heat and generate cold.
    • After Crystal's death, a new Killer Frost debuted as Dr. Louise Lincoln (in Firestorm #21, in March 1984), a friend of the former who gains the latter's powers through the same means in order to avenge Crystal's death. This incarnation of the character made several appearances up until the New 52 relaunch, having been a member of the Injustice League, Secret Society, Suicide Squad, and an independent contractor.
    • During the Forever Evil crossover-event of the New 52 relaunch, Caitlin Snow was introduced as the latest incarnation of the Killer Frost persona (as Caitlin Snow in The Fury of Firestorm: The Nuclear Man #19, in June 2013, and as Killer Frost in Justice League of America #7.2, in September of the same year). This character is a S.T.A.R. Labs scientist in the field of thermodynamics, working in the Arctic Circle.
      • The Arrowverse version of Killer Frost, although identified as Caitlin Snow, also shares the Crystal Frost version's affection towards a member of the Firestorm/Deathstorm entity, in this case Ronnie Raymond.
  • When confronting Caitlin in the forest after finding her, Cisco Ramon called her "Elsa",[4] referencing Queen Elsa from the Disney movie Frozen; both Elsa and Caitlin are pale-haired women with ice-manipulating powers.