Because you like Cookie Monster in Sesame Street

Peter Venkman's "research" projects are designed to get undergraduate students to sleep with him. Though it turns out he can bust ghosts. See them in Ghostbusters.

The Grinch's heart is just too small to appreciate Christmas. See them in Dr. Seuss' How the Grinch Stole Christmas.

Waylon Smithers would do anything for his boss, and would love to do a few things *to* him. See them in The Simpsons.

Anger is a cantankerous hothead whose job is to get others riled up. See them in Inside Out.

Linda Belcher doesn't prescribe to what society deems as "normal." She narrates her life through song, much to the alarm of everyone nearby. See them in Bob's Burgers.

Dewey Finn will rock you. He feels rock and roll in his blood and guts. See them in School of Rock.

The Ice King is lonely and looking for a princess to sweep him off his feet. See them in Adventure Time.

Disgust is a friend who makes sure you stay away from all things gross. See them in Inside Out.

Mother Gothel is a great mother as long as you never, ever, break the rules. See them in Tangled.

Moe Szyslak is the crabby owner of the grimiest bar in Springfield. See them in The Simpsons.

Buddy Pine is an unhinged superfan of superheroes using technology to take down his idols. See them in The Incredibles.