Polterguy

Polterguys (also known as Phantom Guys  ) are Shy Guys that appear only in the Mario vs. Donkey Kong series. They are based on Boo Guys; the name "Polterguy" is based on the word "", referring to their spectral appearance.

Mario vs. Donkey Kong
Polterguys first appear as enemies in Mario vs. Donkey Kong, and are found in Spooky House. Like other enemies in the game, if Mario comes in contact with them, he loses a life. Polterguys cannot be defeated; instead, when Mario presses a Color Switch of the same color as a Polterguy, it turns into a harmless block that Mario can stand on.

Polterguys also appear in Spooky House's boss stage, 4-DK. These Polterguys now have flame-like auras similar to Pyro Guys, though this is only a visual effect, and the usual animation plays if Mario loses a life by coming in contact with them. As they float around in a set pattern, Donkey Kong hits one of three Color Switches, transforming the Polterguy of that color into a regular Shy Guy, which Mario can pick up and throw at Donkey Kong to damage him.

Mario vs. Donkey Kong 2: March of the Minis
In Mario vs. Donkey Kong 2: March of the Minis, Polterguys are known as Phantom Guys and appear in Spooky Attic. They mostly retain their appearance and movement patterns from the last game, serving as enemies that can be turned into platforms for Minis to walk on. In the Construction Zone, Phantom Guys can be used in the Spooky Attic construction kit and Special Kit 3.

Mario vs. Donkey Kong: Minis March Again!
Polterguys appear in Mario vs. Donkey Kong: Minis March Again!, where they now have active wind-up keys on their backs like their walking counterparts. They are also less transparent and have a spectral, vaguely fiery aura that resembles their boss stage appearance from the first game. In addition, they remain in the same spot rather than move in a given pattern, though they still turn to face any Minis present. They are first encountered in Room 4-5.

Mario vs. Donkey Kong: Mini-Land Mayhem!
In Mario vs. Donkey Kong: Mini-Land Mayhem!, blue Polterguys appear as enemies in Area 4-DK. When Donkey Kong summons a Polterguy from a Shy Guy portrait, it simply falls down until it hits ground or girders, then disappears. A Mini Mario breaks if it touches a Polterguy.