Clem is a purple ghost with blond hair with a bald spot, yellow pupilless eyes, a single tooth, a small scratchy patch of facial hair on his chin, and a gravelly redneck-style voice. He wears a white and blue cap, blue overalls with a pocket and a single hole for his tail, a white undershirt, and green gloves.
Luigi initially encounters Clem while the latter is napping. However, before Luigi can sneak away, he accidentally steps on a rubber ducky, causing Clem to stir, and then activate a pipe to spray Luigi as a prank before fleeing, forcing Luigi to stop the release of water.
Soon, Luigi encounters Clem again at the top of the Waterworks, witnessing Clem pull a switch, flooding the Waterworks. As Luigi watches the room flood, Clem scares Luigi by surprise, causing him to fall into the water and drown, only for Polterpup to save him. Luigi is forced to take a detour through the sewers in order to find a way to drain the Waterworks.
He later encounters him in a large reservoir, where Luigi again attempts to avoid waking him, only to end up stepping on a rubber ducky yet again, waking him. Clem gets irritated, but then gets the idea to fill the reservoir. However, after Luigi gets into an inner tube shaped like a duck, and saves himself, he decides to confront Luigi personally.
Clem will attack the player with a paper fan as well as launch mines.
The player needs to manipulate Clem into spinning himself in circles with his fan, then suck his inner tube and launch it into one of the sides of the reservoir, causing it to deflate. Afterwards, the player needs to disembark and approach his prone body. If he regains consciousness, he will be busy putting on another inner tube, requiring the player to flash him as he is busy and then try to suck him in (though it is preferable to use Gooigi and have him suck Clem in while Luigi stays inside the pool). Upon being defeated, Clem will struggle to free himself before being sucked in, humorously releasing several rubber duckies in addition to the floor 10 button which falls into the pool, requiring Luigi to drain the reservoir to get the button.
Names in other languages