The Egg Marine is the stage boss of World 7-2, the Bridge Zone. Piloted by the evil mechanical genius Dr. Robotnik, the Egg Marine is a submersible attack craft capable of firing bursts of up to three fireballs at a time. It happens to be one of Robotnik's earlier designs, though, making it rather predictible. It attacks by surfacing along one side of the arena, firing a volley of fireballs, then submerging, re-emerging on the opposite side, and repeating the pattern.