Polterpup (species)

Polterpups are ghost dogs in Luigi's Mansion: Dark Moon. During several missions in the game, Luigi encounters a sole Polterpup that takes various objects of importance that he needs. These objects range from Keys to Gold Bones. A Polterpup, the only one encountered in the story, may also revive Luigi when he's lost all of his HP if he happens to have a Gold Bone with him. When a Polterpup has taken something, Luigi must track it down using the Dark-Light function. When the Polterpup is found, he must suck it up. Upon being sucked up, their color changes to gold. This single Polterpup, named ??? and sporting a red collar instead of the usual blue, consistently escapes from the Poltergust 5000. It is eventually caught and put in the Vault after the first mission in the Treacherous Mansion.

Polterpups also appear in their own ScareScraper mode: Polterpup Mode. In this mode, the group must find the kennels or locations where the Polterpups are hiding and capture them all. Each Polterpup has 50 HP, except for Big Polterpups, which have 100 HP. Big Polterpups are found only in Polterpup Mode.

In the game's ending, it is shown that Luigi keeps the Polterpup met in the story as a pet. It falls asleep in Luigi's lap at the end of the game.

ScareScraper
Polterpup - Normally very playful and kind, the Polterpups started misbehaving after the Dark Moon shattered.

Big Polterpup - This pooch is big, so it might take more than one ghost hunter to keep him under control!

Campaign
??? - ''I haven't come up with a name for this mischievous and adorable Polterpup yet. He's caused us a whole mess of trouble, but I think the playful tyke just wants someone to take him in.'' (Evershade Valley Ghosts section)

Trivia

 * When a Polterpup goes through a wall, it leaves an imprint, referencing the Slimer from Ghostbusters.
 * Despite being a ghost itself, other ghosts seem to have a dislike of Polterpups, which is shown at the Old Clockworks where one of them steals a clockhand from some Greenies.
 * A Swapnote message regarding Luigi's Mansion: Dark Moon was sent by Shigeru Miyamoto prior to the game's release. According to the note, the Polterpup is Miyamoto's favorite ghost in the game.
 * The Polterpup, ???, is the only ghost in the Vault without a name.
 * Despite only one Polterpup appearing in Story Mode, after capturing it, it still restores Luigi's HP when he is out.
 * Aside from their mischievous behavior, for some reason, Polterpups do not act vicious nor villainous when the Dark Moon is shattered.