The cult-classic TV show Buffy the Vampire Slayer ran for seven seasons and was packed with endless monsters and villains to haunt your dreams. After all, you can't have a slayer without monsters to slay.
From demons who appeared for one good scare to season-long bad guys, Buffy fought them all. On top of the never-ending stream of vampires, Joss Whedon and the writers created countless monsters for the slayers to thwart. Even the Scooby Gang themselves crossed over to the dark side on more than one occasion.
Some villains such as the Trio aren't going to haunt your dreams, unless you find a group of geeks particularly terrifying, but others are the stuff of nightmares, ranging from inventive and powerful villains like the First to an actual giant bug lady whilst drawing inspiration from different cultures and religions.
Vampires, demons, hell-mouth creatures, and actual gods; Buffy the Vampire Slayer left no creepy stone untouched. With so many to chose from it's been hard to whittle them down to just ten.
From Season Two, this giant prehistoric parasite took over Sunnydale High School by hatching hideous eggs. The babies would latch onto humans and take over their motor functions.
This particular monster was somewhat reminiscent of the face-hugger from Alien, and made things much more personal by attacking Buffy's mother and friends. The creature would then drain the life from the host who had become a mindless slave to the Bezoar.
In addition to the eggs, the mother Bezoar was capable of ingesting humans and vampires alike and in the end had to be killed from the inside by Buffy. One of these creatures was hard enough to kill let alone if the babies had grown to their full strength. This was an early - but no less terrifying - monster that crept up on our heroes from beneath their very own school.