King Bill (New Super Mario Bros. Wii)
From the Super Mario Wiki
(Redirected from Missile Banzai Bill)
King Bills are a bright red Banzai Bill variant that only appeared in World 9-3 of New Super Mario Bros. Wii. Unlike Bull's-Eye Bill, they only have a limited homing ability where they will track their target's vertical position and then continue forward once they reach that height. Their animation is very limited as well, always maintaining a horizontal position and never turning to point at their target. King Bill, as well as Ghost Vases are the only new enemies from New Super Mario Bros. Wii that do not return in New Super Mario Bros. U.
The player can defeat it by simply jumping on its head, or by running into it with a Super Star. Also, a King Bill cannot be frozen by an ice ball; it will break the ice and release itself when the ice ball reaches it. Likewise, POW Blocks are useless against them.
King Bills are never seen being fired from a Banzai Bill Cannon.