Boogaloo's Minions are hordes of ghosts who follow the demon Boogaloo.
In ancient times, the Halloween Deal was struck between the demons and Druids. Boogaloo took his army to the Netherworld. 2000 years later, they manipulated Dr. Crowley into breaking the contract and creating a portal to the Other Side. The minions quickly went to work terrorizing the populace, dismantling Ecto-1, freeing their comrades from the Containment Unit, and destroying Dr. Crowley's Anti-Halloween Machine so it couldn't be used to undo the damage. The Ghostbusters managed to trap a few but quickly ran out of empty Traps. Luckily, once the Halloween Deal was restored, the minions and Boogaloo were pulled back to the Netherworld.