Gem Goob

Gem Goobs are rare ghosts in Luigi's Mansion 3. They are Goobs with crystalline bodies that drop gems when defeated. If Luigi finds one, it will panic and run around, trying to escape. They do not take damage while being vacuumed and must be slammed to deplete their health. They have 80-120 HP. Usually, the Gem Goobs hold a white gem, but at The Spectral Catch and the Fitness Center, the ghosts hold a different gem, with the one encountered at The Spectral Catch dropping that floor's red gem. In addition, the Fitness Center has a pair of them: the first one holds that floor's white gem, while the second one holds its purple gem.

Unlike Golden Goobs, they can be captured anytime upon revisiting the same room where the player first found the Gem Goob, likely due to the fact that all of the Gems are needed to unlock the Suction Shot Type-C.