Psycho Derek - One Tree Hill
The guy had a weird crush on Peyton and yet pretended to be her brother. He had a crazy stalker wall with pictures of Peyton, fell out of a two story window – and escaped! Then he held a creepy basement prom with Peyton. He defined creepy, and psycho for that matter.
A - Pretty Little Liars
A terrorized the liars for years without giving away her identity. Let's be honest, even after the big reveal, it's hard to put any one face to the identity since so many people masqueraded as A along the way. Terrorism was A's specialty.
Gareth - The Walking Dead
This guy wore a friendly face while welcoming his dinner to Terminus, but he had no redeeming qualities. Unless you call chopping off Bob's foot, roasting and eating it in front of him redeeming. He didn't even offer the hungy victim a bite!
Talky Tina - The Twilight Zone
Playing with dolls was never scarier than when The Twilight Zone introduced Talky Tina. With Chatty Cathy being a popular dolls on the real market, they took the idea of a little girl’s chatty doll, and made it deadly, and oh-so creepy. Tina was really sweet…if you were nice. If you were mean to her she unleashed her fury, and "The Living Doll" would not hesitate to murder you. Bonus scary? The voice actress who voiced Talky Tina was also the voice of the original Chatty Cathy doll.
The Gentlemen - Buffy the Vampire Slayer
A girl in Buffy's dream said it well enough. "Can't even shout. Can't even cry. The Gentlemen are coming by. Looking in windows, knocking on doors... They need to take seven and they might take yours... Can't call to mom. Can't say a word. You're gonna die screaming but you won't be heard."
Cruella de Vil - Once Upon a Time
Most of the villains on this show have a heart. For some it might be buried deep. Others may have had it ripped out but there’s usually one there. Some back story that makes the villain's evil ways make sense, except when it comes to Cruella. She may be the one character who was simply born bad. As a girl she poisoned her own father, then murdered her step-fathers and eventually trained dogs to brutally maul her own mother to death. When magic blocked her powers, the only thing she wished to have back was the ability to kill again. If that’s not scary, I don’t know what is.