Killer Frost (Arrowverse)

"He gave me the thing that you couldn't. The cure to my illness - embracing who I really am..."

- Killer Frost explains her allignment with Savitar Killer Frost, originally known as Caitlin Snow, is a meta-human criminal who appears in the Arrowverse series, The Flash. The Earth-1 Caitlin Snow appeared in the first two seasons as one of the main protagonists, but become one of the main protagonists turned secondary antagonist in the last episodes of season 3. The Earth-2 Killer Frost appeared as a supporting antagonist in season 2.

The first Killer Frost was a meta-human criminal from Earth-2 who was in league with the evil speedster Zoom. After betraying him, she was imprisoned and kept in a cage by Zoom. When Zoom eventually captured her Earth-1 counterpart, with whom Zoom was in love, Killer Frost realized that Zoom only kept her because she reminded him of her Earth-1 version. Thus, Killer Frost decided to murder her counterpart but before she could do so, she was killed by Zoom.

However, seeing her evil counterpart in the flesh changed Caitlin, who constantly lived in fear of turning into Killer Frost as well. However, exactly this fear led to her slowly turning into Killer Frost. Although she obtained an amulet which contained her meta-human powers, the amulet was taken from her neck in order to unleash her regenerative powers when she almost died. This, in turn, fully unleashed her inner villain, turning her into the second version of Killer Frost and unleashing her onto Central City.

Both versions are portrayed by Danielle Panabaker.

Youth and aiding Team Flash
Both of Caitlin's parents were doctors, which instilled a great respect for science in her and eventually led to her becoming a doctor and scientist as well. After Caitlin's father died from multiple sclerosis, her mother completely devoted herself to her work as a way of coping with her grief. This led her to somewhat neglecting Caitlin which led to the two of them becoming estranged over the following years.

After becoming a doctor like her parents and turning into a skilled neurosurgeron, Caitlin was offered a job at her mother's company but she refused, intending to make a name for herself instead of hiding behind the name of her mother. Instead, she accepted a work offer from Harrison Wells and started working at S.T.A.R. Labs in Central City. There, she developed a close friendship with her co-workers Cisco Ramon and Ronnie Raymond, eventually falling in love with the latter. The two started dating. While at S.T.A.R. Labs, she also developed a bond with the lab gorilla Grodd, who was experimented on by the military on orders of General Eiling.

The night the S.T.A.R. Labs particle accelerator was to be switched on, Caitlin was present at the Lab together with her co-workers. When it was realized that something was wrong, Ronnie and Cisco headed downstairs to save them all but when the accelerator exploded, Ronnie was seemingly killed. Although they did not realize it back then, Caitlin and Cisco both became meta-humans during the incident. When Barry Allen was struck by the explosion as well, rendering him comatose, he was brought to S.T.A.R. Labs where Cisco, Caitlin and Wells tended to him.

After Barry regained consciousness and realized that he became a speedster, Caitlin played an extremely important part in the creation of Team Flash and continously helped Barry and the rest of his team during their mission. She and Barry became close friends. During their adventures, the team also found out that Ronnie was still alive and they managed to recover him and to bring him back to the team. However, when the team later had to destroy the wormhole created in the final battle with Eobard Thawne, Ronnie was killed for good - sending Caitlin into a deep depression as she lost the man she loved twice.

Zoom
Caitlin is only driven out of her depression when Jay Garrick arrives from Earth-2, warning Barry and the team of a sinister speedster called Zoom. Jay starts working together with the team and eventually, he and Caitlin fall in love. When Caitlin learns that Jay is dying from a sickness created by the speed-serum Velocity-9, she and the team promise to save him.

However, when part of the team visited Earth-2 to free the daughter of their team-member Harrison Wells from Zoom's lair, they are confronted by some of Zoom's meta-human mercenarys - Earth-2's Killer Frost among them. To Caitlin's horror, however, Jay is seemingly killed by Zoom when the team returns to Earth-1. This drives Caitlin into depression once more and hardens her against all her teammate's efforts to help. Caitlin realizes that everybody is behaving strangely around her and eventually learns of the existance of her evil-counterpart. However, she promises the team that she would never turn into something like Killer Frost.

Eventually, the team finds out that Jay Garrick and Zoom are the same person and that Zoom was using the team the entire time. Caitlin at first does not believe it but then decides that Jay, whatever his true name, needs to be taken down. Meanwhile, Zoom started preparations for invading and conquering Earth-1. However, he still had feelings for Caitlin which eventually led him to kidnapping her and imprisoning in his lair. During her captivity, Caitlin met her Earth-2 counterpart for the first time, as Killer Frost had been imprisoned by Zoom as well. During the imprisonment, Killer Frost tried to murder Caitlin but was killed by Zoom before she could do so. Eventually, while bringing his meta-human army to Earth-1, Zoom gave Caitlin a choice. She could either remain with him or return to her friends, making her Zoom's enemy. Caitlin decided to return to her friends. Caitlin proved essential in Zoom's downfall, as she managed to manipulate his feelings for her to lure him to the final standoff with the Flash.

Possible future
According to Craig, a member of Savitar's cult, Caitlin will be described as being "glorious and powerful", and Savitar will have "special plans" for her.

In a news report on a television reporting the arrest of Jared Morillo that Barry saw during his accidental trip to May 2017, a subheading reads "Killer Frost still at large". While Barry succeeded in altering the circumstances of Morillo's arrest, with Wally defeating him instead of Barry in January instead, Caitlin's future remains the same. Barry laters reveals to Joe that Caitlin's on the loose and they need to bring her in, prompting him to alert the CCPD. This causes the aforementioned headline.

When Barry visited a possible future, in the year 2024, it is revealed that Caitlin allied herself with Savitar. Moreover, during the aforementioned battle, Vibe's arms were frozen and shattered by Caitlin, forcing him to replace them with bionic arms and subsequently losing his powers. Caitlin, still as Killer Frost, has been locked up in the Pipeline, and still refuses to divulge the identity of Savitar, with Julian as her caretaker.

Becoming Killer Frost
After the Flashpoint-Timeline is dissolved, Caitlin suddenly starts developing symptoms of her meta-human powers. Having witnessed the cold-hearted Killer Frost first hand, Caitlin becomes deeply afraid that she will turn into an equally evil person with no emotions or feelings. Thus, she keeps her powers hidden even from Team Flash and starts searching for a cure on her own. However, when Mirror Master traps Barry in a mirror, Caitlin uses her frost powers to free him from it.

In her desparation, Caitlin even visits her mother and asks for help. She eventually snaps when she cannot stand her mother's distant behaviour anymore, freezing her desk and thus revealing her powers. Caitlin's mother immediately clears her schedule and the two Snow's start running tests to find a way of saving Caitlin. During that time, the two also solve out some of their issues. When Nigel, one of the lab assistants tries to prevent Caitlin from leaving the premisses, intending to use Caitlin's powers for his own benefit, Caitlin coldly freezes his arm solid. With Killer Frost briefly taking over, Caitlin is ready to kill Nigel but her mother manages to appeal to Caitlin and talk her out of it. Caitlin's mother later contacts Caitlin again, revealing that Caitlin's powers will develop faster the more she uses her powers. Caitlin steals power dampeners from S.T.A.R. Labs in order to prevent her powers from spreading but Cisco eventually finds out and Caitlin admits her powers to him. Cisco makes Caitlin confess her powers to the entire Team Flash despite her not being ready for it.

In her fear of becoming Killer Frost, Caitlin ironically becomes more and more like her. When one of Savitar's acolytes is taken by the SCPD, Caitlin, now taken over by Killer Frost, storms into the interrogation chamber and tortures the man with her powers, demanding to know how to find Savitar as she believes that Savitar can take her powers from her. While leaving the precinct, Killer Frost is confronted by Julian Albert whom she swiflty kidnaps in order to force him to locate Savitar and the followers of Alchemy. Julian is able to do so but also alerts the GCPD, prompting Killer Frost to attempt to kill him. However, Barry arrives in time to confront Killer Frost. When Cisco arrives as well, Killer Frost attacks the two, kissing and thereby freezing Barry completely who is saved just in time by a vibe from Cisco. The vibe also knocks out Killer Frost who is then imprisoned in the pipeline. After regaining consciousness, Killer Frost attempts to convince Barry and the team that she is back to normal but this fails. Instead of abandoning Caitlin, however, Barry refuses to give her up and eventually opens her cell, telling her that she would have to kill him if she intends to get out of S.T.A.R. Labs. Although Killer Frost creates an icicle, she is unable to kill her friend and returns to her Caitlin-form in tears.

Attack on S.T.A.R Labs
A mysterious future villain of the Flash named Abra Kadabra appears, stealing from several tech companies in an attempt to build a timeship to return to the 64th century. Abra Kadabra soon finds himself chased after by the Flash and Gypsy, escaping, but not before telling Flash that he knows Savitar's name. Sometime later, he teleports into S.T.A.R Labs and ambushes Caitlin, Julian and Joe West, but is soon apprehended by the Flash and locked up in the Pipeline where he keeps taunting the team about his knowledge of Savitar.

He tells Joe that if he lets him escape from Gypsy, he will reveal Savitar's name so the team can save Iris. Joe agrees, and sets him free, but Kadabra betrays him, claiming that the terms of the agreement have changed. He then collects a mysterious future power source from the Time Vault, and sets off an explosive as Caitlin, Joe and Julian attempt to chase after him upon his escape. The resulting explosion impales Caitlin's side with shrapnel. To evade bringing Caitlin to a hospital where she would be exposed as a meta-human, Caitlin is forced to supervise her own surgery. Initially, all goes well and Caitlin falls asleep after the shrapnel is successfully removed. Later however, her heart rate suddenly spikes,, putting her life at severe risk. Torn between respecting Caitlin's wishes that she'd rather die than become Killer Frost, or to tear off the power-dampening pendant to possibly bring her back, Julian ultimately decides to tear the pendant off, which results in Caitlin's revival power healing her at an enormous speed. Caitlin's wound heal instantly, but she also emanates a cloud of mist, sending the team and herself flying. Once the cloud cleares, Caitlin emerges from the mist fully transformed into Killer Frost and attacks the team.

Soon after her escape from S.T.A.R Labs, Caitlin is wandering around in the snow and finds Savitar. She then asks if Savitar wants to cure her, to bring Caitlin Snow back, to which he replies that he wants the opposite. Caitlin asks why she should trust him and Savitar removes his armor, which causes her to state she'll do anything he wants.

Following Savitar
Once Killer Frost has sworn herself to Savitar, Savitar informs her that scientist Tracy Brand will develop the device that will trap Savitar in the speed force four years from the present. He tells her to kill Brand so that she can never create the device. Thus, Killer Frost heads to the Central City university where Brand is currently located. However, when she storms the university, she finds that Barry, Cisco and H.R. have already turned up to recruit Brand. Killer Frost hurls an ice blast at Brand but Barry jumps in front of it, taking the whole blast. This leaves only Killer Frost and Cisco standing. Cisco tells Killer Frost that he does not want to hurt her and Killer Frost replies that she knows he doesn't. However, she adds that she will and shoots more ice at Cisco, who is taken by surprise and blasted backwards. Meanwhile, Barry gets back up and uses the laboratory equipment to create a small explosion directed at Killer Frost. Driven backwards by the heat, Killer Frost is forced to flee.

She returns to Savitar's lair and informs him that she failed in killing Brand because Cisco and Barry interfered. Savitar is surprised, as he had informed Killer Frost that the two would be present. He wonders whether there is still part of Caitlin in Killer Frost and then reveals to her the importance of Brand's death. He states that the only thing standing between the two of them and true "ascension" to a level above pain and hate is Tracy Brand. He once more tells her that Brand must be eliminated and Killer Frost sets off to murder Brand.

Killer Frost tracks down Brand to the coffee store Jitters. There, Brand is together with H.R. but the two are warned about Frost's arrival when the coffee freezes inside their mugs. They run outside and call the nearby-posted Barry for help. The team assembles around them, just in time to witness Killer Frost arriving. H.R. and Brand run into the city to escape but Killer Frost pursues them by creating a frozen slideway in front of her feet - swiftly speeding after the two high above Central City's streets. Barry, in turn, pursues her and manages to direct her back to Jitters where Cisco is waiting. However, Cisco once again remembers that his friend is still stuck inside Killer Frost and that he might accidentally kill her if he attacks her. Thus, Cisco refrains from attacking Killer Frost and, sensing his weakness, Frost blasts another stream of ice at him. Once more, Barry jumps in front of the target and is hit by the blast and thrown down a stairway. Frost slowly walks down the stairway and tells him that Savitar forbade her to kill Barry. However, claiming that she cannot have him hunt her down, she creates an icicle which she rams into Barry's leg to temporarily slow him down.

Fed up with having to hunt down Tracy Brand, Killer Frost kidnaps Joe's love interest Cecile instead. With Cecile as her hostage, Killer Frost turns up at the West house and warns Joe that Cecile will die should Brand not be surrendered to her. She informs Joe that he will receive a message with an adress shortly. When Joe attempts to stop Killer Frost from leaving with Cecile, Killer Frost uses her ice powers on him.

An hour later, Barry and the team turn up at the address Killer Frost sent them. Secretly, Cisco heads up into the rafters in order to later ambush Killer Frost. When Killer Frost reveals herself, Barry tries to appeal to Killer Frost but surprisingly, Killer Frost already knows what exactly Barry will say and keeps saying the words together with him. After Barry stops talking, Killer Frost laughs a humorless laugh and reveals that Savitar told her exactly what Barry would say to her. She adds that Savitar also told her that Cisco would be hiding in the rafters and activates hidden explosives that blast Cisco off the roof. She then hurls another icicle at Brand which, once more, Barry takes. Once Barry has gone to the floor, Killer Frost freezes his torso in order to prevent him from getting back up. However, she is then hit in the back by Cisco's vibe powers. She quickly gets back up and starts a battle with Cisco, who has finally overcome his fear. Both blast their powers against each other and Cisco eventually gains the upper hand and blasts Killer Frost back several feet. After making sure she is still alive, Cisco takes a blood sample from Killer Frost but before he can do more, Savitar speeds into the room and grabs the unconscious Killer Frost. He then speeds off and takes Caitlin with him.

Past
Caitlin had a brother, Charlie, who died at some point in her youth. Charlie's death deeply affected Caitlin's mother, and she became cold, violent, unfriendly, and antipathetic.

Caitlin was affected by the S.T.A.R. Labs particle accelerator, giving her cryokinetic abilities. Since then, Caitlin cut off all ties to her past life and began calling herself "Killer Frost".

Present
She is first seen attacking thieves who have stolen gold worth two million dollars from the Central City Royal Bank. Claiming that the town belongs to Zoom and those he deems worthy enough to enforce his will, she throws a icicle into the thugs' stomach, killing him. She gets rid of the other heister by kissing him, thereby freezing his entire face. She is then informed by her husband Ronnie Raymond that breachers have entered their world. Killer Frost claims that her favourite activity is killing people from other earths and the two set out to kill the breachers. They hunt down Barry, who has taken the identity of his Earth-2 counterpart, to a café. They demand to know who of the guests is the breacher from Earth-1. Nobody gives himself up and Iris, the wife of Earth-2 Barry, draws her gun to arrest Killer Frost and Deathstorm. Killer Frost activates her power and Barry tries to reason with her, calling her Caitlin. Killer Frost claims that if he really knew her, he would know that she hates the name Caitlin and lunges icicles at him and Iris. Barry saves them by using a table as cover. Barry then uses his speed to grab Killer Frost and Deathstorm and brings them into a park in Central City. They continue their fight and Barry cleverly reflects Deathstorms fireblast onto Killer Frost. Deathstorm grabs her and flies off with her, claiming that their battle isn't over.

After the police department has been tipped off about Killer Frost's and Deathstorm's hideout, Iris, her partner Lawton and Cisco head there only to be disarmed by Killer Frost. Reverb then appears, revealing himself as the employer of Killer Frost and Deathstorm as well as Cisco's Earth-2 doppelganger. Reverb offers Cisco to reign Central City by use of their powers but Cisco turns down Reverb's offer. The Flash arrives and knocks down Reverb. Iris then takes her gun and shoots Killer Frost in the shoulder, causing Deathstorm to viciously attack his opponents. While Barry evades him, he is shot in the back by Reverb. Reverb and Deathstorm then both attack the weakened Barry, who is merely able to dodge their blows. Killer Frost urges both men to stop, as Zoom has ordered them to keep every speedster they encounter unharmed. The same moment, Zoom appears behind Deathstorm and kills him for disobeying him. Killing Reverb as well, Zoom then turns to Killer Frost, claiming that he's glad at least one of his henchmen knows where his loyalties lie. Zoom then leaves with Barry, leaving Deathstorm's and Reverb's corpses behind. Killer Frost drops to the ground in grief. After realising that Deathstorm is truly dead, she flees from the scene.

Helping the breachers
To find out where Zoom keeps Barry, Wells and the rest of his crew track down Killer Frost to show then the way to Zoom's lair. Though she is initially uncooperative and attacks, Cisco manages to convince her to aid them by reminding her of her love to Ronnie, who Zoom took away from her. Killer Frost leads them to Zoom's lair, a cave in the middle of a upright cliff. By use of her power Killer Frost creates footholds for the group to climb. Inside the lair, Killer Frost freezes the chain holding Wells' daughter. When the group is confronted by Zoom, Caitlin attacks him, holding him off long enough for Barry and his friends to escape. Although he eventually overpowers her, Zoom does not kill her but locks her up in Jessie's old cell. There she eventually meets her Earth-1 counterpart after Caitlin has been kidnapped by Zoom. She tries to persuade Caitlin to help her break out of her cell, claiming that in return she would help her fleeing from Zoom's lair.

Caitling indeed manages to weaken the cell, causing the glass to shatter. After this, Killer Frost attacks Caitlin, revealing that she never intended to help her. She reveals that Zoom didn't kill her because she looked like Caitlin. To make sure Zoom doesn't need her anymore, Frost lunges a sharp icicle at her, but Zoom speeds in front of Caitlin, catches the icicle and stabs Frost with it, killing her.