Because you like Yvaine in Stardust
Jane Smith is a stone-cold killer, but you would never know it from looking at her. See them in Mr. & Mrs. Smith.
Helena is a mentally unstable, childish, and completely merciless. And most of all, she's an unstoppable killer. See them in Orphan Black.
Usagi Tsukino may look like a lazy teen, but when Usagi conjures up her alter ego and calls her Sailor Scout team, no villain stands a chance. See them in Sailor Moon.
Warm and caring, Kitty Forman acts like a mom towards all of her kids' friends. See them in That '70s Show.
Beware! Anton Chigurh carries a coin with him, which he forces his victims to flip to decide whether they will live or die. See them in No Country for Old Men.
A vampire hunter, Integra Hellsing doesn't tolerate failure, least of all her own. See them in Hellsing.
Sansa Stark is a fan of all things pretty. Unfortunately, her life is about to get extremely ugly. See them in Game of Thrones.
The only thing standing between Rocky Balboa and glory is the person facing him in the boxing ring. See them in Rocky Series.
Brilliant, violent, and only a little insane, the Joker doesn't listen to anyone except the voices in his head. See them in DC Extended Universe.
Bart Simpson is an aspiring juvenile delinquent who doesn't want you to have a cow, man! See them in The Simpsons.