Shell Mario

Shell Mario is a form of Mario that Mario can become in New Super Mario Bros. by touching a Blue Shell. It allows him to use the Hammer Suit-like ability to dodge the attacks of enemies when he crouches, tucking into it. However, if he ducks while running he will hide in the shell and the shell will slide through the world, bashing through lots of enemies. This maneuver is called a Shell Dash.

Trivia

 * In any of the boss fights with Bowser Jr, Mario or Luigi can use the shell dash to knock the young koopa out, similar to what you do in later fights, where you need to throw koopa shells at him before jumping on him.


 * Shell Mario is also an excellent swimmer, with better control and faster speed than Super or Fire Mario.