Underchomp

The Underchomp is a red, yellow, and blue 3-headed Chain Chomp, that acts as a guard dog of The Underwhere in Super Paper Mario.

Mario, Luigi, and Bowser face against this beast in a far different way from other enemies in the game; they fight the creature in a turn-based battle, though not in the same fashion as other Paper Mario games. The fashion of this battle is comparable to classic Dragon Quest or Final Fantasy battles, as there are many options to choose from.

Battle Strategy
Using Bowser to attack the Underchomp is the most effective way to defeat the massive enemy. If the heroes found Piccolo the Pixl, then it will make the battle that much easier. By using Piccolo's power, the heroes can make the Underchomp fall asleep for several turns.

Trivia

 * The Underchomp may be based upon the legendary hellhound Cerberus, a giant, three-headed dog who guarded the gates of Hades in Greek mythology.