|Species Origin||? Blocks and Hammer Bros.|
|Average Behavior||Slamming into you|
|Habitat(s)||Carried by Background Bros.|
|First Appearance||Super Mario Bros.: The Popstar Crossover|
|Latest Appearance||Super Mario Bros.: The Popstar Crossover|
? Bros. are enemies encountered in Super Mario Bros.: The Popstar Crossover, hence the name, they are golden Hammer Bros. with a ? Block for a body, a golden head on it, 2 golden shoes under it, it attacks by slamming into you, one is only thrown once when a Background Bro is exposed and throws it and runs away.
Hence the name, it has a golden ? Block for a body, but still shows the golden head and shoes.
It makes it's debut in this game, they are only seen when thrown by Background Bros. when exposed once a level, they attack by slamming into you, if they failed to slam into you, they will fall down, providing you to ground pound it, when ground pounded, it will provide a rare item, then run away, while it's running away, you can kick something at them, upon being hit will shrink more and disappear, and will provide you a coin upon it's death.