Because you like Mrs. Hudson in Sherlock

This high school queen bee has everything, including a genius-level IQ—a fact Lydia Martin keeps hidden to maintain her image. See them in Teen Wolf.

Due to his eagerness to hang with his kids and general goofiness, Phil Dunphy comes across as the fourth child of his family. See them in Modern Family.

Don't worry about this forensic scientist offing you unless you're a serial killer yourself. (You're not, right? Just checking.) See them in Dexter.

Norma Bates may look like a harmless housewife, but don't let that fool you. See them in Bates Motel.

Kathryn Merteuil may be a vain sociopath, but you won't be able to look away. See them in Cruel Intentions.

A genetic experiment engineered to be the perfect assassin, Agent 47 is cold, professional, and lethal. See them in Hitman.

Ava may just be the perfect woman. So long as she can pass a Turing test. See them in Ex Machina.

Raz is a 10-year-old boy who mostly stays in his own head, which makes sense since that's where he is strongest. See them in Psychonauts.

SpongeBob SquarePants lives in a pineapple under the sea. Absorbent and yellow and porous is he. See them in SpongeBob SquarePants.

Randy Marsh is a geologist and Nobel Prize winner who is into binge drinking, starting riots, the Food Network, and P.F. Changs. See them in South Park.

A great galactic bounty hunter, Samus Aran is not as good at expressing emotions. See them in Metroid.

Jenna Rink is physically 30 but emotionally 13. She has a better excuse than most. See them in 13 Going on 30.