Barnacle Boy is the sidekick of the Mermaid Man. His actual name is Kyle, and he is 68-years old. He often refers to Mermaid Man as an "old coot," and in the true tradition of sidekicks, he takes the physical load off his hero and takes it himself. Barnacle Boy once became a villain and fought against Mermaid Man, but they have already patched things up. He is also the enforcer of security at the Rock Bottom Museum. When it comes to powers, his abilities are similar to Mermaid Man's, and he also had sulfur vision.