Kate Argent was the sister of Chris Argent, aunt of Allison Argent, and the sister-in-law of Victoria Argent. Kate was a member of a group of Werewolf Hunters. She was killed by Alpha Werewolf Peter Hale.
She is buried in Beacon Hills Cemetery. Her gravestone reads "KATHERINE ARGENT 1983-2011"
Throughout Season 1, Kate pushed Allison to learn more about her family and their mission to hunt werewolves.
In The Tell she gave Allison a silver pendant featuring a wolf. In Heart Monitor, she directed her to the French legend of La Bête du Gévaudan and the connection between the beast in the story and the Argent family. In Lunatic, Kate taught Allison to use a Taser gun.
Kate was fearless and possibly sociopathic when it came to dealing with werewolves.
During a later confrontation with Derek Hale in The Tell she seemed to enjoy taunting and torturing him before trying to kill him. She constantly pushed Chris Argent to act against The Alpha while her brother urged restraint as they gather more information.
The character’s dialog was rife with sexual innuendo. She made suggestive comments to Derek while torturing him and teased Scott during the family dinner in Magic Bullet.
In Formality Kate told Allison the truth about werewolves as she tortured Derek for information in hope of finding the Alpha and the other Beta. Kate and Derek were involved in a relationship similar to that of Scott and Allison. Kate told him the sex was great but that she was just using him to find and kill the rest of his pack.
In the season finale, Code Breaker, Peter Hale held Kate hostage and threatened to kill Allison unless Kate apologizes for what she had done to his family. Saying Kate’s apology didn’t ring true, Peter ripped out her throat. Later her corpse is seen by the police who discover the necklace around her neck. With this being done, she is blamed for the Hale House burning down, and the murders of her co-conspirators.
- “You know how every family has its secrets? Ours are a little different.” — Kate to Allison in Co-Captain.
- “You don't have to be psychotic to be a killer. You just... need a reason and even then, sometimes... You can surprise yourself.” — Kate to Allison at the Hale House in Wolf's Bane.
- “I don't know whether to kill it or lick it.” — Kate to Derek in The Tell.
- “Sweetheart, there are werewolves running around in the world. Everything's a joke to me. How else do you think I stay sane?” — Kate to Allison in Formality.