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 the Spooky House world. Like other enemies in the game, coming in contact with Mario will cause him to lose a life. Polterguys cannot be defeated normally; when Mario presses a button that is the same color as any of the ghosts, they turn into harmless platforms with Shy guy masks, allowing Mario to pass by.

Polterguys also appear in the Spooky House's boss stage. 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 will hit one of three Color Switches, transforming the Polterguy of that color into a regular Shy Guy that 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 they are renamed Phantom Guys, and appear in the Spooky Attic stage. They mostly retain their appearance and movement patterns from the last game, serving as obstacles to the Mini Mario toys that can be turned into platforms. In the Construction Zone, Phantom Guys can be used in the Spooky Attic and Special Kit 3 sets.

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 Mini Marios present. They are first encountered in Room 4-5.

Mario vs. Donkey Kong: Mini-Land Mayhem!
In Mario vs. Donkey Kong: Mini-Land Mayhem!, Polterguys appear as enemies that Donkey Kong summons in Area 4-DK.