Mario With a blue shell on his back
The Blue Shell is a powerup in the Super Mario series. They first appeared in Super Mario World. They make Yoshi sprout wings and fly. They also let Mario slide around the ground and kill enemies in New Super Mario Bros. In the Super Mario Strikers series, they are similar to Green Shells, but they freeze enemies when they hit them.
In Mario Kart Wii, the Blue Shell comes with wings, and is a tracker bomb that blows up the leading racer and anyone near it.