Karai is an anti-heroine from the Teenage Mutant Ninja Turtles series.
History
Abandoned by her parents at a young age, Karai was taken in and adopted by Ch'rell, the Utrom Shredder (in the original comics, the Shredder's only daughter is was biological offspring named Pimiko and Karai had no relation to him). Trained in Ninjutsu and an aspiring practitioner of bushido, Karai first appears as one of the highest-ranking members of the Foot Clan, similar in status to the Shredder's adopted son Hun (who holds a grudge against her); eventually, she becomes the clan's leader.
Throughout the series, she appears both as an ally and enemy to the Turtles, sharing a sort of close love/hate relationship and friendship with Leonardo; a dualism that plays a part in most of her appearances. She was the only Foot member who knew that the Shredder was really an Utrom. After Ch'rell's exile at the end of Season 3, Karai spent all of Season 4 and Season 5 trying to make the Turtles pay for this. When she appeared as a guest of April and Casey's wedding, her vendetta with the Turtles was confirmed to be finally over.