Xander's fear was created during his sixth birthday. In the party, a clown chased him and he became so frightened that he had what can be assumed an embarrassing accident.
During Billy Palmer's nightmarish manifestations of all Sunnydale residents, Xander found a trail of chocolate bars in Sunnydale High. The Killer Clown then appears from behind a curtain, chasing Xander now with a knife while laughing. Xander then teams up with Willow and Giles, and decides to confront the clown, and finally punches him.
When Billy finally wakes up, the Killer Clown disappeared along with all other magical constructs.
Behind the Scenes
- This character is a possible reference to It (1986), the horror novel in which an entity exploits the fears and phobias of its victims, appearing primarily in the form of a clown.