Beetlejuice's parents have a chance to join the Neitherworld's Society of Oldest and Moldiest Families, but to prove their pedigree have to produce their family's (literal!) Coat of Arms, which is somewhere in Beetlejuice's possession. When cleaning Beetlejuice's room to find the Coat of Arms proves unsuccessful, Beetlejuice and Lydia must travel to the World of Lost Items and find it.
—Tony Scheinman