The Mermaid Man Collectible Underpants are an article of clothing that only appear in the episode "Pineapple Invasion."
The Mermaid Man Collectible Underpants resemble regular underpants. They are green and blue in color with Mermaid Man's "M" on them as well.
Role in episode
- It is unknown if there is a Barnacle Boy version of these underpants.