Dragon Wario (Wario Land: Super Mario Land 3)
Dragon Wario is one many forms in the Wario Land series.
It first appeared in Super Mario Land 3: Wario Land, where it could be activated by touching a Dragon Pot. Instead of getting a hat, he gets a seemingly mechanical dragon on his head. Then he can breathe fire, but it only lasts a few seconds. It works underwater too.
The next time Wario could get these powers was in Virtual Boy Wario Land by obtaining the Dragon Hat. This game differed in that he couldn't bash things with his shoulder as a dragon.
It also appears in Wario: Master of Disguise and works similarly, although it can be used throughout a level. Dragon Wario falls through thin floors in Wario: Master of Disguise, assumedly because he is very heavy in this form, as evidenced by the fact that he can't jump very high. Unlike in Wario Land, this form does not work underwater. Also he can swim in lava and can have blue fire if he gains a mastery gem. Dragon Wario somewhat resembles a Kritter in this game.