Rump Command

Rump Command is a large area inside Bowser's tail in Mario & Luigi: Bowser's Inside Story. Once there, Mario and Luigi meet two Evoglobins, and the player also plays a space invaders style mini-game in which they shoot red, green, and blue orbs towards his heart to revive and make Bowser grow. However, Bowser can only grow when in peril, meaning that Mario and Luigi only need to explore here when Bowser's in danger.

This is also the most visited place by Mario and Luigi inside Bowser (4 times).