Flat Wario is one of Wario's 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.
Flat Wario makes a cameo appearance in WarioWare: Touched! at the end of the game. At the end of Wario-Man's cutscene, the guru 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 possesses no actual importance to the gameplay.
A possible reference to this form of Wario can be found in Mario Golf: Toadstool Tour. In one of his failure animations, Wario holds a huge boulder over his head and tosses it into the air in rage. The boulder eventually comes down again and hits him in the head, flattening him in the process. He then proceeds to walk off to the right of the screen in a manner similar to Flat Wario.
Artwork
Original artwork from Wario Land II 
Artwork from Wario Land 4
| Wario Land II | |
|---|---|
| Main characters | Wario • Captain Syrup |
| Supporters | Gull • Hen • Owl • Turtle |
| Bosses | Awabō • Big Kamukamu • Bobo • Cave master • Dunk • Ghost • Giant bee • Giant snake • Giant spear man • Mecha Kuri |
| Chapters | Chapter 1 • Chapter 2 • Chapter 2* • Chapter 2** • Chapter 3 • Chapter 3* • Chapter 4 • Final Chapter • Final Chapter* • Final Chapter** • The Really Final Chapter |
| Conditions | Ball • Bouncy Wario • Bubble Wario • Crazy Wario • Fat Wario • Flat Wario • Frozen Wario • Hot Wario • Puffy Wario • Tiny Wario • Zombie Wario |
| Enemies | Bee • Bird • Chūta • Cook • D-Bat • D.D. • Drill • Flame • Gaugau • Ghost • Grunt • Gugi • Inamazu • Kamukamu • Pecan • Penguin • Pirate Goom • Pogo Guy • Punch • Rooster • Tobī • Togemen • Tsuriuo • Utsutsubo • Weight • White puff • Wizard • Yukimaru • Zombie |
| Objects | 10 Gold Coin • 100 Coin • Alarm clock • Big Block • Bonfire Block • Brick • Coin • Doughnut block • Enemy Block • Ice block • Kotsuheri • Lance • Spike • Stove • Switch |