In the Mario Kart series, a Green Shell will shoot forward in a straight line. Unlike the Red Shell, the Green Shell does not home in on opponents, but is able to ricochet off of walls. After about five bounces, the Green Shell will break. In Mario Kart 64, Green Shells remained on the track until they either fell off or collided with a racer or item. In less spacious areas, Green Shells are especially deadly because they bounce all over the place, making it very hard to dodge them.
Green Shells may come in singles or triples- a single shell may be fired individually or held behind a racer, and triple shells will almost always rotate around the racer's kart, allowing it to be used as a battering ram-like weapon or a defensive barrier against bananas and other stray items. In Mario Kart: Double Dash!!, however, triple Green Shells were only available with Koopa Troopa and Paratroopa, and was held in the kart rather than rotated around.