Unwelcome Guests is an expansion for the second edition of Gloom, introducing 55 transparent cards that add new layers of macabre humor and strategy. This set brings in Unwelcome Guest characters who move between families, providing persistent effects that influence gameplay dynamics. Additionally, the expansion adds a new family—the malodorous Malone mob—and introduces persistent effect icons on Modifier cards, allowing their special effects to remain active even when covered by another card.