Sonic Roar!

Sonic Roar is Bowser Jr.'s Super Ability, used in the Wii game, Mario Strikers Charged Football. However, the move can only be used when Bowser Jr. obtains his special item which, like everyone else's special item, is depicted as his own head. Once executed, Bowser Jr. will roar incredibly loudly, and send a sonic wave in front of him. This shrinks all the players that it hits, both his opponent's team and his own team. Any shrunken player will move much slower, and will be unable to catch up to normal-sized players. Shrunken players are also unable to shoot as well as they do when full-sized. The effects wear off over time. Sonic Roar acts similarly to Bowser Jr.'s Mega Strike, which also involves a loud burst of sound.