Because you like Norman Bates in Psycho
Despite Norman Bates' typically kind and shy personality, he is also prone to occasional violent outbursts. See them in Bates Motel.
Alex DeLarge likes his favorite milk-based, drug-laced cocktail. It helps him get in the mood for a night of "ultra violence." See them in A Clockwork Orange.
If Jack Torrance is one of his moods, you'll be the unlucky victim of the most bone-chilling, sinister yellers around. Bring your own axe. See them in The Shining.
Years of constant assault by mean classmates, rude teachers, and her abusive mother is making Carrie White want to fight back. See them in Carrie.
James Gordon happens to be the one guy in Gotham City with proper morals who doesn't also run around in a cape. See them in DC Extended Universe.
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.
Norma Bates may look like a harmless housewife, but don't let that fool you. See them in Bates Motel.
Jean-Baptiste Grenouille may have a phenomenal sense of smell, but he has a weak sense of morality. See them in Perfume: The Story of a Murderer.
Jim Stark is a teen torn apart by what the world asks of him. See them in Rebel Without A Cause.
Just because Dracula wants to suck your blood doesn't mean he's not a gentleman. See them in Dracula.
A Vietnam vet, Travis Bickle spends his days driving his taxi and watching porn flicks. See them in Taxi Driver.