Spine Coaster

Bonecoasters are rideable creatures made of bone used to make Mario and his company pass through the lava pit. They only appear in World 8-7 from New Super Mario Bros. Wii, a stage that can be unlocked by finding the secret exit in World 8-2. It also appears in multiplayer versus mode. In the end of the way of a Bonecoaster, it dives into the lava and never gets out of it again. There's a total of four Bonecoasters.

Bonecoasters will be very useful throughout the World 8-7, because they will help Mario and his company to get the Star Coins in this stage and will also prevent them from falling into the lava. However, the Bonecoasters make risky maneuvers, passing through lava geysers and into the lava itself. Bonecoasters stand the weight of Mario, Luigi and both Toads over it. However, if all characters perform a Ground Pound over it at the same time, it will fall making everyone fall onto the lava. Also, Bonecoasters can not hurt any character.

Trivia

 * "Bonecoaster" is a combination of the words "bone" and "roller-coaster".
 * The Bonecoaster somewhat resembles a Bone Dragon, but its head is smaller in size, and there are no spikes on its back.
 * The bonecoaster is probably a dead snake. (possibly even a dry snake).