Mermaid Man and Barnacle Boy is an episode from Season 1.
Whilst pestering Squidward, SpongeBob and Patrick learn that their heroes, Mermaid Man and Barnacle Boy, are in fact living in the Shady Shoals underwater retirement home, and they try to bring the two out of retirement, much to the annoyance of the geriatric Bikini Bottom superheroes who only want their TV fixed. SpongeBob and Patrick go through all kinds of hilarious antics to reunite their superhero pals and eventually succeed, by Barnacle Boy getting tired of them and calling other former superheroes, thereby creating Mermaid Man and Barnacle Boy's new show: The New Adventures of Mermaid Man and Barnacle Boy.
- When SpongeBob and Patrick devote themselves to help Mermaid Man and Barnacle Boy, music from Jurassic Park is heard in the background.
- Mermaid Man's outfit and super powers are both very similar to Aqua Man, while Barnacle Boy is a parody of Aqua Lad. Mermaid Man and Barnacle Boy are also parodies of Batman and Robin.
- The Mermaid Man & Barnacle Boy theme as introduced in this episode is called "The Lineman", which was originally composed by Sam Spence for NFL Films.
- Barnacle Boy was not the original sidekick of Mermaid Man. Originally, he was to hang out with an old coot named Barnacle Bill. Barnacle Bill, due to his marine mishaps, had a body made entirely out of driftwood. He also had flippers for arms and legs, wore a hat that looked similar to SpongeBob's Krusty Krab workhat, smoked through a wooden smoker (though he produced bubbles instead of smoke), and had a head that resembled that of the famous cartoon sailor Popeye. Stephen Hillenburg, though, couldn't find a use for Barnacle Bill, so he replaced him with Mermaid Man's current sidekick, Barnacle Boy.
- Mermaid Man illegally moves one of his checkers into a red space before the screen switches to "King me!"
- When Mermaid Man and Barnacle Boy say "Dog paddle away!" and start dog paddling, you can clearly see Mermaid Man's socks are missing. After, they return when they dog paddle around SpongeBob and Patrick.
- When SpongeBob and Patrick are first asking the man at the front desk to see Mermaid Man and Barnacle Boy, an article on the inside of his newspaper reads, "School Drop Out Rate Increases and Global Ocean Warming".
- When SpongeBob and Patrick pretend their doughnuts are rings, Patrick first grabs a chocolate, but is later shown with a glazed.
- SpongeBob quotes: "Do you remember in episode 346 when the food supply in Atlantis was severely low?". That must mean that SpongeBob knows about Atlantis already, but in Atlantis SquarePantis, he does not. However he could of thought it was a fake place since Mermaid Man and Barnacle Boy is a TV Show.