Iron ball

Big Steelies are large invincible balls that appeared in Super Mario World in the last battle with Bowser. He drops these from his Koopa Clown Car. Mario can jump over them to avoid getting hit. Mario can also spin jump on them without getting hurt.

In the Super Mario World episode "Send in the Clown", Bowser attempts to defeat Mario in one scene by dropping a Big Steely on him, which Mario dodges.

Big Steelies also appear in Super Mario 64 and Super Mario 64 DS, in Bob-omb Battlefield, Tall Tall Mountain, Tiny-Huge Island, and Battle Fort. They come out of holes and roll in the ground. If Mario gets hit by one, he will lose two wedges of health. In the original game, they are indestructible, but they could be destroyed with a Super Mushroom in the remake.