Because you like Brian Griffin in Family Guy

Darcy Lewis is a razor-sharp scientist studying things that science can't explain. See them in Thor.

Leonard "Bones" McCoy is passionate, moral, and ready to stitch you back together. See them in Star Trek.

Years of brutal winters, foreign invasions, and crippling loneliness have left Russia's mental state far from wholly intact. See them in Axis Powers Hetalia.

Kevin Khatchadourian is a disturbed, affect-less teen on a dark path. See them in We Need to Talk About Kevin.

The ever-cheerful Tonks can change her appearance at will, but she can't seem to get rid of her clumsiness. See them in Harry Potter Series.

Yuri is living in the afterlife, which takes the form of a high school where no one dies. But if you follow the school's rules and live a "normal" life you vanish. See them in Angel Beats!.

Susanna Kaysen is an aspiring writer, despairing young woman who struggles with suicidal thoughts. See them in Girl, Interrupted.

Just call Jeff Lebowski The Dude. Or His Dudeness, Duder, or El Duderino if you're not into that whole brevity thing. See them in The Big Lebowski.

Stella Grant is an organized, orderly optimist living with a dangerous disease. See them in Five Feet Apart.

April Ludgate doesn't like sunshine. She's more of a blood and guts kinda girl. See them in Parks and Recreation.

Shana is a red-haired warrior with a black-and-white worldview. See them in Shakugan no Shana.

Living with a curse, Kyo Sohma is sick of being treated like garbage his whole life. See them in Fruits Basket.