Mario has given us several types of bros enemies. There are the Hammer Bros, the Ice Bros, Fire Bros, flying hammer and sledge hammer Bros. The Fire, Ice, flying, and Sledge Hammer are different versions of the Hammer Bros. Another type of Bros character was introduced in Super Mario World. That character is the Sumo Bros.

Sumo Bros are stocky koopa enemies that attack Mario, Luigi, and Yoshi in Super Mario World, which is when they made their debut. Since that game they have appeared in future games. They are considered a semi-regular occurring enemy.

They resemble to some extent a Hammer Bros except they are heavier and more bulky. Given how they have bros in their name it is likely they are related to the Hammer Bros enemies. It is highly speculated they are cousins to the Hammer Bros. Another enemy the resemble is charging chuck, which are koopas that wear American Football gear.

Like all Koopas their main objective is to slow or slow Mario and his friends down. They can sometimes appear in groups of 2 or being single, again similar to a Hammer Bros. They have very thick armor and can create lighting bolts when they do their sumo stomps. In some versions they can also create fire by doing their classic sumo stomp.

There next appearance was in the Mario Party games. In these games they would stomp to create lightning or fire. The characters have to avoid these attacks. If a player is struck by lightning or fire they are eliminated from that particular game.

They appear in the Super Mario Bros Wii games serving the same role as Super Mario World. In this game they will create lightning or fire to slow Mario and his friends down or serve as an obstacle. In their recent game they where seen serving as guards of Bowser's castle.

Appearance- They are bulky orange and yellow Koopas. However, their shell is black. They also wear a black helmet. The helmets have thorns or spikes on top of them. It appears they wear brown boots or shoes. Most of the time it appears they are frowning but this is because their mouth points downward.

Personality- Not much is known about their personality. However they have at times stated "try to get past our lightning/fire. "You cannot pass when referring to Mario and his friends". Based on these quotes it seems they are confident in their abilities. In addition, it also suggests that they take their roles as obstacle courses or guardians very seriously.

Abilities- Sumo Bros can be tough enemies to beat just like a Hammer Bros. They can create fire or lightning with a traditional sumo stomp hence how they got their names. Moreover, the spike on their helmets makes using jumping attacks harder. They are also immune to fireballs and they cannot be ate by Yoshi.

Attacks/Moves- Their classic Move is their sumo Stomp. When they do their Sumo Stomp it will create either lightning or fire. The lightning/fire will linger. Thus, their opponents have to wait till the lightning /fire clears before trying to attack them. In some games they can hide in their shells. While it is not an attack it is a good defensive ability, the spikes on their head can nearly prevent jump attacks. If an opponent tries to jump on one they will be hurt. However, it is possible to do a spin jump off their helmets but this does not defeat them. In some versions they can jump in the air and create more lightning/fire when they land.

Weaknesses- They are immune to fireballs in most games. They are weak to POW blocks and star power. In some games the player can pick up a shell and throw it at them. In Wii games they are shown to be weak to ice. Ice cools them down.

Relationships

Allies

Bowser, Bowser Jr, and Koopalings. They are very loyal to Bowser and his family. They understand their roles. Given how they are sometimes placed in castles. It is likely that they are very trusted to guard the castle.

Hammer Bros and other Koopas- They are likely related to the Hammer Bros. They get along well with them and can provide assists in battles. They all share the same goal make Bowser and his family proud. They are also part of the Koopa Troop.

King Boo?- They have not interacted with King Boo. But given how King Boo is a trusted ally of Bowser it is likely they get along well with the other king.

Enemies

Mario and Luigi- They are enemies due to the brothers foiling their masters plans. Also the brothers have found ways to defeat them.

Yoshi- Like Mario and Luigi Yoshi has defeated Bowser. Even though Yoshi cannot defeat them unless he uses a POW block or Star Power they are still hostile toward him.

The Sumo Bros are Koopas and can be formidable opponents due to the power of their attacks and their defensive abilities. As I stated it is highly speculated they are cousins to the Hammer Bros. On the other hand, they also resemble charging chucks so they might be related to them as well. Regardless, they are trusted members of Bowser's Koopa army.

Their role is to be an obstacle or guardian. Even the Mario Brothers admit they are tough. Their powerful lightning and fire attacks make them difficult to get past. Careful timing is needed to defeat them.

In conclusion, they are heavy hitters in the Koopa Army. Since they perform the ceremonial and traditional Sumo Stomp that is likely how they got their name. Their bodies are also loosely based on Sumo wrestlers. It is easy to see how Sumo served as the inspiration for these characters.