Splounders are more like obstacles than enemies, but can be a nuisance in some of the levels in which they are found. You will find them in pretty much any level that has Plessie, except for a single one in 3D World. They can be defeated by pretty much any attack and don’t really hurt the player at all, if you happen to touch them. Should you, though, the player will bounce off of them. In fact, jumping on top of a Splounder will let you get some extra height, which might allow you to reach otherwise inaccessible areas.