Sumo Bros.

From SMWiki

Sumo Bros. are fat brown Koopas who generally stand on top of blocks elevated from the ground. They shuffle back and forth in a limited area. Every so often, they stop, raise their leg, and stomp down. The force of their stomp shoots down a lightning bolt. The lightning bolt, however, does not harm you if you touch it. Once the lightning bolt hits solid ground, it explodes into a wall of flames which spreads for two blocks in either direction. Almost as soon as the flames die down, the Sumo Bro. stomps again, sending down more fire.

The "Brothers" in the Sumo Bros. name would imply that they're related to the Hammer Bros. from the previous games, but their smooth shells and general features are more like an unhelmeted Chargin' Chuck. Like Hammer Bros., Sumo Bros. are typically defeated by hitting the block they're standing on from beneath (this is not an option if they're standing on cement blocks). They have a single spike growing out of their heads which prevents them from being stomped, but a cape swipe or shell can defeat them.

Hacking information

Sumo Bros. are sprite 9A, and their lightning is sprite 2B. They use yellow palette A. Sumo Bros. can only be used with the plains enemy set. (SP4 = GFX09)

Their flames eat up a lot of memory, which can cause slowdown if too many Sumo Bros. are used in the same area. There appear to be issues with the flames and some carryable items like Keys or Springboards. Sometimes weird glitches can occur where the carryable object will vanish from Mario's hands and appear on top of the flames, "riding" them until they subside.