Killjoy



Killjoy is a medal awarded and in Halo 3, Halo: Reach and Halo 4 multiplayer for killing a player who is on a Killing Spree of five kills or higher. It is represented by an octagon with a crossed-out smiley face in the middle.

Trivia
Earning a Killjoy on a Halo 3 Mythic map will unlock the Awww, Too Bad achievement.