マックスマン

The grandson of Sneagator (Shocadile), an old-generation Akuma Choujin that was defeated by Mantaro's father. He can transform into a giant athletic shoe. Mantaro figures out that a shoe's worst enemy is stepping in feces, while in the anime version, Kid Muscle had an alien from Planet Kinniku called a Stinkbug.

(Source: Wikipedia)