Sneaker

Sneakers are a type of ghost that appear in Luigi's Mansion: Dark Moon. They usually appear in a group of three or with two or three Greenies. They have 25 HP. In D-2: Hit Rock Bottom, 3 Boos are showed to imprision a Sneaker, a Greenie and a Slammer into red crystals, which transforms them into their Strong forms.

Abilities
Sneaker will sneak (as the name says) behind Luigi and scare him, disrupting him while he is sucking ghosts with the Poltergust 5000. They can attack by strangling Luigi, causing him to lose HP.