Ring of Pleh (5e Equipment)
From D&D Wiki
This ring has ten charges. When you wear this ring, you can use a charge and an action to cause a splatter of green, brown, or gray (DM decides which when first giving the item) goop to cover up to 1 sq. foot of material (or person) in a gross mess. It smells a little off and is hard to clean (It can take 10 minutes of scrubbing a hard surface or a hour of washing clothes), but is otherwise harmless. The ring regains 1 charge at dawn each day.