Iron ball

Big Steelies are large invincible balls that Bowser drops from his Koopa Clown Car in Super Mario World. Mario can jump over them to avoid getting hit.The only time you see them is in the battle with bowser at the end of the game.

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.

A similar object appears in Super Mario 64.It also appears in the DS version of Super Mario 64. It is possible these versions can be destroyed by wario.This is currently unconfirmed.