Monsters are not supposed to scare adults. Serial killers, gangs, torture, guns, sickness, terrorism and crippling bankruptcy are the things meant to scare us.

However, every once in awhile, a series will create a monster believable enough to actually scare us. We may not jump or cry while watching the show, but the memory of it sticks with us. It's unsettling when you're alone at night or lost in the woods. In honor of Halloween, here are the scariest TV monsters of all time.

6. Smoke Monster /Man in Black ('Lost')
This choice may seem a bit cartoonish. After all, "monster" is even in the title. However, if you find yourself alone in a jungle area and the wind makes the right noise through the trees, you can't help but look for smoke. Victims are helpless against this force -- which can become a man sometimes. Even after watching the whole series, do you really know how to defeat the Smoke Monster?


5. Human-Visitor Mutants ('V')
For those old enough to have watched the original 'V,' the lasting image of a reptilian tongue shooting out of the human baby discomforted us all through youth. You couldn't see a baby without the thought popping in your mind. In the re-imagined series, they didn't show that moment, opting for a creepy baby tail instead. Still, the thought that some people are actually reptiles underneath is scary and the basis of various conspiracy theories.


4. Russell Edgington ('True Blood')
With the current vampire craze, it may seem too obvious to pick the Vampire King of Mississippi. Still, the idea of a 3,000-year-old vampire with unlimited resources and a pack of werewolves at his command is a bit unsettling. Not that he needs them since no other vampire can match his strength or speed. When Edgington ripped the newscaster's spine out as he started reporting vampire news, don't say you didn't shiver.


3. Observers ('Fringe')
While we don't know the Observers' true intentions, they're just plain creepy. They're men without eyebrows, who seem to appear from nowhere and are always watching. If you're a 'Fringe' fan and you see a man in a suit without eyebrows, guaranteed you'll be freaked. Actually, even if you shave your own eyebrows off, you'll scare yourself.


2. Anthony Fremont ('The Twilight Zone')
Emotionless children are disturbing. That is why 'Children of the Corn,' 'The Omen' and 'The Ring' are all great horror movies. In the episode 'It's a Good Life,' Fremont looks like Opie but has evil god-like powers and lords over a small Ohio town. The locals don't even know if the rest of the world exists anymore. That feeling of isolation and knowing a monster is in a child's body will give you nightmares.


1. The Flukeman ('X-Files')
The inbred pig farmers, poltergeist, aliens and Eugene Tooms are all scary monsters from 'The X-Files,' but this human-worm mutant continues to linger with us. In episode 'The Host,' the flukeman lives in the sewers, pops out unexpectedly to grab victims and plants flukeworms in their bodies. If it doesn't kill the victim immediately, the worm will later. You may not be scared now, but wait until you're by dark water, a pipe or in a dark outhouse -- you'll think of the flukeman.


What TV monsters scare you?