Mermaid's purse decoration is an item that can be obtained from prawn balls with a 7% chance, and put inside the Aquarium in a player-owned house. It can be looted every week for either 20 mahogany planks or 20 teak planks. Your diving suit in the aquarium must be at least a mermaid hunter suit to be able to loot a mermaid's purse. You can have a maximum of 3 mermaid's purse decorations in your Aquarium.
- "Mermaid's purse" is the colloquial nickname for the egg cases of oviparous sharks, skates, and chimaeras.