Because you like Grunkle Stan in Gravity Falls
Marge Simpson is a mostly happy housewife and subscriber to Sponge and Vacuum Magazine. See them in The Simpsons.
Gene Belcher dreams of a future in the limelight, and he doesn't let his lack of talent hold him back. See them in Bob's Burgers.
C is for cookie, and that's more than good enough for him. See them in Sesame Street.
A short-tempered guy, Bowser is determined to wreak havoc on the Mushroom Kingdom. See them in Super Mario Bros..
The self-described "ghost with the most" knows the ins-and-outs of specter life like no other. Just ask him. See them in Beetlejuice.
Krusty The Clown somehow makes life sillier and more somber at the same time. See them in The Simpsons.
This lab mouse has one thing on his huge brain: trying to take over the world on a nightly basis. See them in Pinky and the Brain.
Moe Szyslak is the crabby owner of the grimiest bar in Springfield. See them in The Simpsons.
Donkey is proof that if you're annoying enough you can change the world; he's the reason that his friend Shrek does, well, anything. See them in Shrek.
A scary monster on the outside, James P. Sullivan is really a softie on the inside. See them in Monsters, Inc..