Flat Wario
Flat Wario is one of Wario's many, many transformations in the Wario Land game series. If crushed by a falling weight in Wario Land 2-4, Wario is squashed flat, shortening his jump and drastically affecting his speed. However, he can glide smoothly in the air to reach places previously unattainable, and slip through tiny cracks in walls. Certain machines and enemies will return Wario to his original shape, as well as getting wet.
Also, in Wario World, the boss DinoMighty as well as many other monsters and obstacles can smash Wario into the ground and flatten him, although there is absolutely no use for this.
Flat Wario makes a cameo appearance in WarioWare: Touched! at the end of the game. At the end of Wario-Man's cutscene, the angel that Wario stole the DS from is mad from before, so he whacks him on the head with his cane. As a result, he turns into Flat Wario.
In Wario Land: Shake It! Wario can be flattened by large objects (such as blocks) that fall on him, however it possess no actual importance to the gameplay.
Artwork
Original artwork from Wario Land II 
Artwork from Wario Land 4
