Sumo Bros are enemies from the Mario series. They appeared in Super Mario World and New Super Mario Bros. U. They usually stomp the blocks to summon electric bolts that usually make fire. To defeat them, you must hit the block above them, which flips them on their shell, so you must stomp their belly.
Sumo Bros appear in Morton's and Wendy's castle, acting the same way they did, also Sumo Bros appear in one normal level, 8-3.