Prince Bully is a special type of Bully, as he is silver in color and will actually spit fireballs. Unlike the normal Bully, though, the arena for Prince Bully doesn’t allow you to knock him into a pit or lava. When you enter the level, you should notice that there are clear pipes on the sides. Those will be the key to defeating the Prince Bully. As for his attacks, Prince Bully will charge at you like normal Bullies, but he can also shoot fireballs.
He will always shoot out a fireball after knocking into him, as well as after each time he takes damage. In order to defeat Prince Bully, you will need to knock him into the clear pipes. Once he gets close enough, he will “teeter” on the pipe, so you will need to give him a little nudge to make him get sucked into the pipe. Prince Bully will be all compact once he comes back into the arena, which is your cue to run into him again to make him take damage. Do this a total of three times in order to win, earning yourself another Green Star.