From the Super Mario Wiki
The Wild Swing-Ding is a powerful move that Wario could perform in Wario World. When grabbing an enemy, if the player spins the in a circle in either direction, Wario will start spinning the enemy. After a few spins, Autoswing will take over and Wario will spin without input from the player. At this point, it is possible to control Wario with the . After 23 spins, Wario will let go of the enemy.
In addition to defeating the enemy Wario is holding, the Wild Swing-Ding damages or defeats any enemy that Wario contacts while he's spinning.