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. It is located in Underwhere Road. Beating the Underchomp is Dorguy the Third's test.

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. Boomer is a great choice for damaging and defeating the Underchomp.

Trivia

 * The Underchomp is based upon the legendary hellhound Cerberus, a giant, three-headed dog who guarded the gates of Hades in Greek mythology. He shares the same weakness; Music.
 * Despite being referred to as a "3-headed Chomp," it isn't really three-headed, but instead three Chain Chomps tied to the same post.
 * The card of the Underchomp refers it as a "special breed" indicating that's not the only existent Underchomp.