King Bill

King Bills are a new sub-species of Bullet Bill that so far have only appeared in the last level of New Super Mario Bros. Wii, in World 9-8. King Bills are invincible, being unable to be beaten through any maneuver or item, and only avoided through outrunning and reaching the end-level flagpole.

It's very large in size, taking up nearly the entire screen, which makes it much larger than the previous biggest Bill, Banzai Bill. It is the biggest non-boss enemy of the game, being beaten out by Bowser's giant form after Kamek's spell in Bowser's Castle.

There are a total of 10 King Bills in New Super Mario Bros. Wii.