Rollodillo

Rollodillo is an armadillo-like boss in Super Mario Galaxy 2. It is fought in the Boulder Bowl Galaxy in the mission Rock and Rollodillo.

Appearance
Rollodillo is a large beast with a reptilian-like face and mammalian body which is covered in a thick, blue rock like substance. It has an armored hide made of pieces of an indestructible rock which covers the majority of its body minus it's soft unprotected rear, face, and underbelly.

Strategy
It attacks mainly by rolling around the planetoid in a fashion similar to a boulder. Mario can only fight Rollodillo while Rock Mario. There are a total of two rounds. When Rollodillo gets dizzy and stops rolling, Mario needs to transform into a boulder and ram into its weak spot, its rear; a Spin Attack is rendered useless against this boss. Mario will need to hit Rollodillo's rear four times. After this, the boss explodes and grant Mario the Power Star.

Trivia

 * Rollodillo shares its boss theme with Sorbetti, Prince Pikante, and Peewee Piranha.