|Species:||Merman (Formerly Human)|
|Job:||The Champion Superhero of the Undersea Deep!|
|Interests:||Crime Fighting, watching television|
Mermaid Man is a semi-retired superhero. His name is a portmanteau of mermaid and the lesser-known merman, the latter being the actual name for the male version of a mermaid. Eventually on July 8, 2012 Ernest Borgnine (The voice of Mermaid Man) passed away. Mermaid Man has been in one episode since then. It is now unknown if Mermaid Man will appear after that and what his role will be.
Mermaid Man is a semi-retired superhero who has aged well past his prime. His costume mostly resembles the costume of the comic book hero Aquaman, with the addition of a star-shaped mask, a scallop-shell bra, and a pair of fuzzy slippers. Mermaid Man's underwater lair and method of crime fighting is a parody of Batman, and his "Invisible Boat Mobile" is a parody of both the Bat Mobile and Wonder Woman's invisible jet. He wears a star shaped mask because it allows him to breathe underwater. It was given to him by 2 mermaids (Mermaid Man Begins). He has an obsession with the word "Evil!” Mermaid Man used to be a fit and strong individual years ago. However, now that he is retired, he is a little out of shape.
 Season 1
|6||Mermaid Man and Barnacle Boy
||Mermaid Man and Barnacle Boy are SpongeBob's favourite heros. As SpongeBob hears that they are retired, he wants them to rebecome super heros and SpongeBob tries a lot of things for that.|
|Mermaid Man and Barnacle Boy II
||SpongeBob wins a mystery item from the Mermaid Man and Barnacle Boy show.|
 Season 2
|31||Mermaid Man and Barnacle Boy III
||SpongeBob and Patrick are left charge of the Merma-lair.|
 Season 3
|45||Mermaid Man and Barnacle Boy IV||SpongeBob shrinks Bikini Bottom with Mermaid Man's Belt.|
|Mermaid Man and Barnacle Boy V||Barnacle Boy is being treated immaturely, so he decides to go on the dark side with The Dirty Bubble and ManRay.|
His sidekick is Barnacle Boy, who he treats like a child (many broccoli) although he is very old. Mermaidman appears to be in the advanced stages of senility, often forgetting what he was talking about, or what he was doing. This is not a problem for SpongeBob SquarePants and Patrick Star, who unconditionally adore the two heroes and managed to coax them out of retirement and back into television. SpongeBob has appeared with them in eight different shorts — often involving a super villain, a Super Gadget, or some combination of the two. In one episode, he and Patrick made a film about the heroes.
Mermaid Man has several nemeses that he fought long ago. The Dirty Bubble, a being made from dirty bubble soap, Man Ray, a humanoid stingray who is Mermaidman's arch enemy and at one point Mermaidman kept him frozen in the Mermalair, the Atomic Flounder, a fish who can shoot nuclear blasts from his mouth, and the Moth, a humanoid moth who steals light and according to Mermaid Man, he has been searching for the Moth for 57 years. (The reason it was 57 years was because the Moth is really small, and imagine trying to search the same moth!)
Mermaid Man enjoys watching television and playing checkers with Barnacle Boy. He eats almost anything. His favorite foods are meatloaf, mashed potatoes, broccoli, Krabby Patties and ice cream.
According to Mermaid Man, his powers are all in his costume. He uses abilities similar to Aquaman's such as: summoning and controlling sea creatures, high speed swimming (used to create an effect dubbed the Raging Whirlpool), water balls, and the ability to survive underwater. While Mermaid Man retains all of these abilities, they are not as powerful as they were in his prime.
In addition to this, Mermaidman's Belt is a wide array of various weapons, most commonly seen as some kind of beam or ray. The only one named is the Shrink Ray which shrinks things, but various effects were created when SpongeBob used the belt on Squidward trying to reverse the Shrink Ray's effects. His belt features other powers such as Building Obliteration Button, Chin Cam, and various radioactive beams that cause bizarre mutations and various effects to the subject, such as causing them to suddenly catch on fire, turn inside out, or to be cut in half by scissors. They are only briefly shown, all afflicting Squidward. This seems to be a reference to both Batman and Space Ghost.
 Mermaid Man and Barnacle Boy's Rivals
- Reflecto (Arch Nemesis 30 years ago)
- The Dirty Bubble (Main Arch Nemesis)
- Man Ray (Most Dangerous Enemy)
- SpongeBob and Patrick (Mermaid Man and Barnacle Boy, Mermaid Man and Barnacle Boy IV, Mermaid Man and Barnacle Boy V and Mermaidman vs SpongeBob)
- Themselves (Mermaidman and Barnacleboy V)
- Kelp Thing
- Sheldon J. Plankton
- Squidward and Sandy (to Barnacle Boy when he joined EVIL)
- Every Villain is Lemons (EVIL)
- The Moth
- The Sinister Slug (as seen in Mermaid Man and Barnacle Boy II)
- The Atomic Flounder (before he retired)
- The Dreaded Jumbo Shrimp (As seen in The Bad Guy Club For Villains)
- Prawn (As Seen in Battle for Bikini Bottom)
- Drippy Brothers Studios' actors of Mermaid Man and Barnacle Boy, because the Drippy Brothers Studios have decided to use "actors" in their Mermaid Man and Barnacle Boy movie and ruin the name of Mermaid Man and Barnacle Boy.
- Mermaid Man and Barnacle Boy (First appearance)
- Mermaid Man and Barnacle Boy II
- Mermaid Man and Barnacle Boy III
- Mermaid Man and Barnacle Boy IV
- Mermaid Man and Barnacle Boy V
- Mermaid Man and Barnacle Boy VI: The Motion Picture
- Night Light
- Mermaidman vs SpongeBob
- The Card
- Back to the Past (him and younger self)
- The Bad Guy Club for Villains (as younger self)
- SpongeBob's Last Stand (does not talk)
- Mermaid Man Begins
- Super Evil Aquatic Villain Team Up is Go!
 Catch Phrases
- "Who are you?"
- "If you want to grow up strong like me, leave room for seconds"
- "Buy More Cards!"
- "WAAA! Now our dreams of being big screen heroes will never come true! And the worst part is, I can't remember why I started crying!"
- Mermaid Man: BONCO!
- Barnacle Boy: It's "Bingo!"
- Mermaid Man: Get your hands off me woman!
- Mermaid Man: And remember...Stay on the path of evil!!!
- Barnacle Boy: It's "Stay away from the path of (imitates Mermaid Man) evil!"
- Mermaid Man: Oh. What is evil?
- Barnacle Boy: (slaps his head) D'o-oh! Bro...mum...mum...Oh
- "Remember kids, no one can imprison you for reading!
 Film and Television
- The Adventures of Mermaid Man and Barnacle Boy:
(Original TV Series)
- The New Adventures of Mermaid Man and Barnacle Boy:
(Present TV Series)
- The Mermaid Man and Barnacle Boy Movie (Drippy Brothers Studio)
(Fake Movie, they made a movie and they used actors. This movie was a box office success and met with positive reviews, but the movie was really a hoax.)
- The REAL Mermaid Man and Barnacle Boy Movie (Fan Made):
(The real Mermaid Man and Barnacle Boy Movie)
- The Further Adventures of Mermaid Man and Barnacle Boy:
(Only seen in a Krusty Krab commercial)