Because you like Buddy in Elf
An infamous vampire, Alucard is a one-man killing machine with a philosophical side. See them in Hellsing.
Pro: Johan Liebert is handsome and charming. Con: he's also a sociopathic killer. See them in Monster (TV Show).
Rose Hathaway is a reckless, rebellious smartass who's training to be a royal vampire guardian. See them in Vampire Academy.
An aloof punk rock goddess, Nana Osaki has a surprisingly big heart. See them in Nana.
Mikasa Ackerman is a near-perfect soldier who won't break her stone-faced expression whether she's killing foes or protecting loved ones. See them in Attack on Titan.
Did he ever tell you the definition of insanity? Just wait, and this psychopath will do just that. See them in Far Cry 3.
Norma Bates may look like a harmless housewife, but don't let that fool you. See them in Bates Motel.
A vampire hunter, Integra Hellsing doesn't tolerate failure, least of all her own. See them in Hellsing.
Other people's opinions have never mattered much to Haruka Nanase, and they aren't going to start to do so now. See them in Free! Iwatobi Swim Club.
For Dana Scully, sometimes looking for extreme possibilities makes you blind to the probable explanation right in front of you. See them in The X-Files.
The son of Death has an obsession with perfection and symmetry. See them in Soul Eater.