User blog comment:Panchito Gomez/Any Episodes?/@comment-1762932-20130607200028

I have an idea you could use.

"The Other Hero" - ''Mermaid Man is on his way to stop a robbery when he sees another Mermaid Man already at the scene and stopping the robber! Mermaid Man decides to get to the bottom of this, and with Barnacle Boy and SpongeBob's help, he sets off to find out what this is all about. When they finally find answers, the team are shocked. Was the other Mermaid Man really what he seemed to be? Who was the person behind all this? And more importantly, will Mermaid Man ever be able to fight crime again?''

It's probably a bit too vague, but I still think it's alright.