Gem Goob

Gem Goobs are rare, blue ghosts in Luigi's Mansion 3. They are gem versions of Goobs, similar to Gold Greenies from Luigi's Mansion: Dark Moon. They are found very rarely throughout The Last Resort and drop a gem if defeated. If Luigi finds one, it will panic and run around, trying to escape. If Luigi does not capture it in time, it will escape and can no longer be captured.

Golden Goobs, another rare variety of Goobs, also appear throughout the game, and are very similar to Gem Goobs. They also drop treasure if defeated.