A mixture of ectoplasm and fish oil turns Rajeev into a muscle-bound merman who becomes an instant celebrity, and the fame gets into his head and causes him to ignore Spencer. But when his fishy smell turns away his admirers and an amorous seal chases him, merman-Rajeev turns back to Spencer and Billy Joe to get his human legs back.
Meanwhile, Rajeev enjoys his newfound fame, with children wanting to see him up close and ask for his autograph. However, a seal emerges from the beach and takes a liking to the merman, who desparately tries to wriggle away from the lovestruck beast.
Spencer tries to break some records and feats of his own, but an angry beach-goer beats him up. As the beach dude angrily stomps off, a repentant Rajeev drags himself toward Spencer, apologizing for his arrogance. Somehow, Billy Joe concludes that motor oil is the opposite of fish oil, which they attempt to use as an antidote.