Bowser Suit
The Bowser suit was a machine used by King Boo in the game Luigi's Mansion as the final boss. However all is not as it seems as it could actually be Bowser himself! Madame Clairvoya states that Bowser was dead and that some ressurected him. It also is a able to spit out an infinite amount of fire and spike balls from its mouth. Strangely enough once you defeat King Boo and take his crown and turn him into a painting, He is also seen with Bowser standing up and his head on. He also has his crown on to in that painting despite Luigi taking it when he was sucked up in the Poltergust 3000. The Bowser suit also speaks no english whatsoever and only roars. At the end of Mario is Missing, Bowser shown dying onscreen in the game, despite it being a kids. Its possible that this is how Bowser died or that it was merely another Bowser Suit.