The Description in E. Gadd's vault says:
"I haven't come up with a name for this mischevious 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."
The official website states, as well as the above:
"These playful canines have a strange and voracious appetite. They tend to eat objects you need, running off with them at exactly the wrong moment."
Luigi takes Polterpup in and adopts him at the end of the game.
The polterpup also appeared in Scarescraper at polterpup mode and surpris mode. You need to use The dark light device to search for the dog house and find the polterpup. The regular polterpup had 50 HP while big polterpup had 100.
- When Polterpup passes through a wall, he leaves a imprint behind, similar to Slimer from Ghostbusters.
- "Polterpup" is a portmanteau of "Poltergeist" and "Puppy". Thus giving it the name, "Polterpup".