Bubble Wario

Bubble Wario is one of Wario's many transformations in the Wario Land series of games. To achieve this transformation, Wario must touch a bubble while swimming underwater. He will then become trapped inside it, allowing him to endlessly float upward. To become normal Wario again, he simply had to reach the air above, or hit a barrier. While inside the bubble, Wario had the ability to resist currents in the water.

Trivia

 * In a microgame from WarioWare: Touched!, a sprite of Bubble Wario appears on-screen.
 * Bubble Wario was one of three Wario transformations appearing in Densetsu no Stafy 3, along with Flaming Wario and Puffy Wario in Wario's cameo appearance in Undersea Ruins.