Clem

Clem is the tenth boss encountered in Luigi's Mansion 3, a redneck mechanic living in the Boilerworks who guards the Floor 10 elevator button.

Appearance
Clem is a purple ghost with blond hair, yellow, pupilless eyes, a single tooth, a small scratchy patch of facial hair on his chin, and a redneck-style voice. He wears a white and blue cap, blue overalls with a single hole for his tail, a white undershirt, and green gloves.

Luigi initially encounters Clem while the latter is napping. However, before Luigi could 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 and saves himself, he decides to confront Luigi personally.

Battle
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's busy and then try to suck him in (though it's 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.

Trivia

 * If the player is far away enough from him during his battle Clem will usually fall asleep.