Shell Mario
Shell Mario (also known as Koopa Mario[1]) 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 or runs downhill or on level ground for long enough 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.
Shell Mario is back in Mario & Luigi RPG 3. The Blue Shell is an item found in overworlds. If Mario and Luigi are outside Bowser's belly, Mario can go in Blue Shells by strucking Blue Shell blocks found in some areas, and turn into Shell Mario. Luigi can then hit Mario using his hammer, and this will make Mario go into the shell, spinning straight forward. This can be used to hit blocks in areas which Mario and Luigi cant directly go into. It serves a similar purpose to the Kooper and Koops partners in the Paper Mario series. This power-up was introduced by a group of Blue Paratroopas.
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 the player do in later fights, where the player needs to throw koopa shells at him before jumping on him.
- Shell Mario also has better control and faster speed inside water, than any other variation of himself. This may be a reference to real-life turtles.