Unicycle Shy Guy
From the Super Mario Wiki
Unicycle Shy Guys are a variant of green Shy Guy in Paper Mario: Color Splash. Only one group of them is found in the game, riding on a unicycle in The Emerald Circus. There are eight Unicycle Shy Guys riding the unicycle, and Mario must defeat them by jumping on them one at a time. They attack Mario by riding their unicycle into him. If they are not all defeated in one turn, more Shy Guys will come and replace the defeated ones.