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 Caitlyn Snow, is a meta-human criminal who appears in the Arrowverse series, The Flash. Two different versions of the character have appeared throughout the seasons.

The first Killer Frost was a meta-human criminal from Eart-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 Caitlyn, 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.

Past
Both of Caitlyn'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 Caitlyn'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 Caitlyn 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, Caitlyn 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, Caitlyn 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, Caitlyn 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, Caitlyn and Wells tended to him.

After Barry regained consciousness and realized that he became a speedster, Caitlyn 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 Caitlyn into a deep depression as she lost the man she loved twice.

However, when part of the team visited Earth-2 and told Caitlyn of the meta-human criminal Killer Frost, her counterpart on that earth, Caitlyn became afraid that she would eventually turn into this cold-hearted killer as well.

Becoming Killer Frost
to be added

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.