Corpse Humping, widely known as Teabagging, refers to the act of repeatedly crouching while standing over the dead "body" of a killed enemy, intended to mimic a sexual act. Online players teabag most frequently as a victory dance to insult and aggravate the victim. Doing so, however, can distract the performer from their surroundings, leaving them open to death from another player or the victim (after having respawned). The crouching action was originally created for the purpose of avoiding getting hit or to hide, but online players mostly use the crouching feature for corpse humping. An alternative to corpse humping could be meleeing or shooting (given that one is not using an explosive weapon, or one with limited ammo) the body, just after the victim was killed.
In Halo 3 and Halo 3: ODST, Bungie included a "dead reflex" so when a player teabags the head of a dead opponent, the opponent's head moves up to the player's crotch. In contrast, Halo 2's reflex was only to move up and down, while in Halo: Combat Evolved, there was no change or head movement whatsoever.