Preppops are stronger versions of Peppops. Unlike Peppops, which are green, Preppops are blue. They can spit out green, poisonous bubbles too.
Like Peppops, Preppops can't be killed with jumps. They're bouncy if they hit Mario anywhere other than the bottom. They can also spit bubbles, which can be sent back at them with a cape to kill them. Usually, though, they jump over the reversed bubble. They cannot be made dizzy, unlike Peppops. Only stars or bubbles can kill them.