Because you like Pinky in Pinky and the Brain
Applejack's practicality complements her caring nature. She is the loyalest of friends and the most dependable of ponies. See them in My Little Pony.
Joey Tribbiani's true passions in life are acting, sandwiches, football, sex, and asking ladies, "how you doing?" See them in Friends.
Poison Ivy is a seductive, venomous botanist laments the fact that there are so many people to kill, yet so little time. See them in DC Extended Universe.
The only defense Earth has against alien invaders are giant robots in the hands of pilots like Kaworu. See them in Neon Genesis Evangelion.
If Lisbeth Salander can hurt a bastard who deserves it by digging up stuff about him, she feels good. See them in The Girl with the Dragon Tattoo.
Gollum is slimy and seething with hatred, the last person you would want to meet in a dark cave. See them in The Lord of the Rings.
Number Five is a 58-year-old man trapped in his 13-year-old body. See them in The Umbrella Academy.
Morticia Addams hates anything bright and cheery and loves all things ghoulish, ghastly, and violent. See them in The Addams Family.
Chaos is what killed the dinosaurs, and there's nothing Jason "J.D." Dean loves more than chaos. See them in Heathers.
There is never a dull moment with Jim Moriarty: expect booze and sing alongs in between all of the homicide. See them in Sherlock.
Phil Coulson is a deadly field agent with the demeanor of a friendly dad. See them in Marvel Cinematic Universe.