"Mermaid Man and Barnacle Boy" is the first segment of the sixth episode of SpongeBob SquarePants. As the title suggests, it is the episode that marks the first appearance of Mermaid Man and Barnacle Boy.
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, thereby creating Mermaid Man and Barnacle Boy's new show: The New Adventures of Mermaid Man and Barnacle Boy. When Mermaid Man sits down, a comic book bubble appears and dramatizes the word "SIT!!". This is an obvious pun on the old Batman Series. The phone gets broken, and when Mermaid Man hangs up the phone, the bubble appears again and says "HANG UP!". Will our heroes ever get their phone fixed? Tune in next week and find out. And when SpongeBob winks, a yellow bubble comes up and says "WINK!!!!" The ironic thing about this is that in most comic books, the dramatization of simple words usually comes in on action fighting scenes, but in this SpongeBob episode, it exaggerates the word dramatization.
- When Patrick takes the doughnut from the box, it is orange, but when they "unite", it is replaced with the chocolate one which was left in the box. After that scene, it changes to the normal doughnut again.
- 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 "Dogpaddle, away!" and start dog paddling, Mermaid Man's socks are missing. Afterwards, they return.
- 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 Soars."
- Mermaid Man's belt is yellow in this episode.
- The old captain is played by the man who guards the gates at Nicktoons Studios in Burbank, CA.
- When Mermaid Man and Barnacle Boy come out of retirement, their first "villains" are SpongeBob and Patrick.
- This is the first episode to use music from the NFL, "The Lineman," which is the theme for most of the Mermaid Man and Barnacle Boy episodes.
- The Adventures of Mermaid Man and Barnacle Boy is a parody of the 1960s Batman TV show.
- Before SpongeBob and Patrick are watching TV, when Mermaid Man talks with Barnacle Boy, there were two Old Man Jenkins, Green and Blue.
- In this episode, the superheroes are revealed to have come out of retirement, but in later episodes, they seem to be still staying in Shady Shoals, there is proof of this as seen in the episodes Night Light and Mermaid Man and Barnacle Boy VI: The Motion Picture.