Yoink

Yoink is a multiplayer medal in Halo: Reach that is awarded when a player steals another player's kill when they are attempting the animated assassination. It is the opposite of Showstopper, which is gained by killing an enemy that is assassinating a teammate.

Trivia

 * Its appearance is superficially similar to the Maybe Next Time Buddy achievement in Halo 3.
 * It may possibly be a reference to a Red vs Blue episode, in which Sarge manages to steal Andy and then Lopez while Caboose is facing the other way, both times saying 'Yoink' or a variation on the term, 'Double yoink'.