From the Super Mario Wiki
How to use the Spin Pipe
Spin Pipe is a Special Attack used in Mario & Luigi: Bowser's Inside Story.
When using this attack, Mario and Luigi stand on top of each other. After that a giant pipe falls on them. The player has to remember where each brother is. After that, the pipe starts rotating and after a while it falls on selected enemy. The player has to press the corresponding brother button depending on which brother's side just fallen. If successful, the attack continues, otherwise it will fail. As the brothers land more and more hits, the pipe will begin to spin more erratically, making it harder to keep track of which brother is at which end. This attack will cost the player ten SP to use. To use it, Mario and Luigi have to solve Kuzzle's first puzzle, which will turn into the Attack Pieces required for the move. If the selected enemy is defeated, the attack will then switch to the next enemy.
Names in Other Languages
||"Vorti" (meaning a Vortex),"Tubo" (Tube)