Stumpet

Stumpet is an exceptionally rare and powerful enemy found in Barrel Volcano in Super Mario RPG: Legend of the Seven Stars. Stumpets seem to be formed from cooled magma which is shaped into a miniature volcano (which also resembles tree trunk, which is probably what it's name is derived from). Stumpets are apparently incapable of moving, despite this drawback they are still a force reckoned with as their Va Va Voom and Backfire attacks are almost uneven in ferocity, luckily the attacks most be charged up ("getting furious!") so they are defenseless for a time.

Interestingly Stumpets are capable of spewing Magmuses, enemies with high defense. This may mean that Magmuses are created by Stumpets or at least live in them, possibly meaning the two species may have a symbiotic relationship.

Trivia

 * Among the unused sprites of Super Mario RPG: Legend of the Seven Stars, there is an enemy named Lumbler, which is a Stumpet lookalike. The only noticeable difference is Lumbler's blue color.