Buffy the Vampire – Episode 110: Nightmares

In this episode, one of the main characters, Xander,  comes face to face with his worst fear, clowns.

The maniacal clown lay a trap of candy bars on the floor, which Xander followed. The clown then jumped out with a knife and tried to kill him.

Apparently, the character Xander had a bad experience with a clown when he was six.

First Aired: May 12, 1997 
Story by: Joss Whedon
Teleplay by: David Greenwalt
Directed by: Bruce Seth Green 
Guest Stars: Mark Metcalf as The Master, Kristine Sutherland as Joyce Summers, Andrew J. Ferchland as The Anointed One, Dean Butler as Hank Summers