"I'm the thing that monsters have nightmares about."
Buffy Summers, Vampire Slayer
Olaf: "HA HA! PUNY RECEPTACLE! YOU DO WELL TO FLEE, TOWNSPEOPLE! I WILL PILLAGE YOUR LANDS AND DWELLINGS. I WILL BURN YOUR CROPS, AND MAKE MERRY SPORT WITH YOUR MORE ATTRACTIVE DAUGHTERS, MARK MY WORDS -- OOH! ALE! I SMELL DELICIOUS ALE!"
Olaf the Troll, Triangle
Olaf is one of the funniest characters ever to appear on Buffy the Vampire Slayer. Olaf used to be a human centuries ago but in 880 A.D was turned into a troll by Anya (who called herself Aud back then) after he cheated on her with a load-bearing bar matron. After his transformation, Olaf adjusts to life as a troll and happily wreaks havoc for years until he gets cursed and turned into a crystal by a group of witches. The two episodes he appears in are some of the funniest episodes of Buffy the Vampire Slayer. In 'Triangle' he is released from his crystal and goes on a rampage searching for delicious ale, virgins to make merry with and nice, plump babies to eat. All of Olaf's lines in 'Triangle' were written in capital letters to symbolize his loud, booming voice. In 'Selfless' we see in a flashback what he was like as a human and how he was transformed into a troll by Aud. The scene was filmed intentionally to look like a grainy, poorly made horror film and has scared villagers fleeing from Olaf the Troll screaming "Run! Hide your babies and your beadwork!" and "The troll is doing an Olaf impersonation!" while others pelt him with fruits and various meats.
"I wear the cheese. It does not wear me."
The Cheese Man to Giles, Restless
The Cheese Man was technically not a villain, but he was one of the strangest creatures that Buffy ever encountered, so I thought it would be fun to include him. The Cheese Man was a magical construct that manifested in the dreams of the Scooby Gang in the episode "Restless". In the episode, Buffy and her friends are each visited by the spirit of the first Slayer, Sineya, in their dreams. The First Slayer gives them all nightmares where she hunts them down and tries to kill them. The Cheese Man appears in all of their dreams as a bald man wearing glasses and holding cheese slices. He serves no purpose and always interrupted at a strange time to say something cryptic about cheese slices. He is a delightfully weird character who fitted in very well in an episode that had the characters trapped in their dreams.