"X" Bumpers are presented as flat, round signs with red edges and a black "X" mark on a yellow background. They also float in midair.
"X" Bumpers are only featured in Special Stages, where they are placed on the edges of the tubular course.
Since the player moves with continuous speed ahead and cannot stop during Special Stages, "X" Bumpers can prevent players from falling off the course by falling towards them. This causes the playable character be bounced backwards a small distance, similar to a Bumper, giving them a chance to turn away from the edge. However, an "X" Bumper will disappear after hitting it once.