Everyone's got their own idea of what's truly frightening. I'm not talking about people or things who just are scary because they're dangerous or despicable. I mean things that truly keep you awake at night, afraid to turn out the lights. Afraid to be home alone. Afraid to fly on a plane. There are a few characters on television over the years who've stuck out more than others as being truly frightening to a handful of us TV Squadders, and we've put together a list (surprise!) of characters who have haunted us for years. If we're digging up old unforgotten nightmares of your own, well, sorry about that.

The list is numbered, but it doesn't necessarily mean these are ordered. Like I said -- we all have a different definition of what truly frightens us. Make sure you list your own in the comments. Click on a number below to get started.

#10 #9 #8 #7 #6 #5 #4 #3 #2 #1

Character: Eugene Tooms
Show: The X-Files
Episodes: "Squeeze", "Tooms"

Eugene Tooms is, hands down, the scariest monster I've ever seen on television (including my fear of some Muppets). He showed up twice during the first season of The X-Files, in episodes called "Squeeze" and "Tooms". He was a freak show who was more than 100 years old. He went into a long hibernation every 30 years after eating five human livers. Tooms had evolved so that he could lengthen his body and squeeze himself into the smallest of places, such as a toilet or an air vent. Part of what scared me about him was that he could easily bypass typical safety features in your home!

(S01E03) Forget the werewolves, the green bugs, the camoflauge forest-dwellers, the inbred pig people and the aliens. You, Eugene Tooms, are the scariest monster ever to grace The X-Files.

Squeeze is the first MOTW (Monster of the Week) episode of The X-Files and it's a doozy. The writers take us off the government-covers- up-aliens-on-earth storyline and focus on a major freak who has ten-inch long fingers and rips the livers out of five victims every 30 years. The experts at The X-Files wiki say FOX requested the script change-up away from aliens. Apparently, the idea came when one of the writers saw an air duct outside their office and wondered whether someone could sneak up inside it. Tooms' obsession with liver came from creator Chris Carter's recent trip to France where he ate a lot of foie gras. That, and the liver is just a funny organ.