Images: Viacom Media Networks/The Everett Collection

When Stephen Hillenburg and company first pitched SpongeBob SquarePants to Nickelodeon, they dove headfirst into their totally unique concept, bringing along models of the principle characters from the show and giving a performance that split the sides of all the studio heads. After that first belly laugh, SpongeBob was greenlit and kids have been bobbing along to his catchy theme song ever since the show debuted in 1999.

Over the course of SpongeBob's 12 seasons, many superstars have drifted onto the show, from David Bowie to Mark Hamill, and that includes a string of classic TV stars whose work was honored by the animated series through scenes that paid great tribute to their iconic shows. 

Wondering which classic TV stars swam laps around SpongeBob in his hometown Bikini Bottom? See all our favorite fishes below!

1

Ernest Borgnine and Tim Conway as Mermaid Man and Barnacle Boy

Tim Conway cracked us up on The Carol Burnett Show, but on SpongeBob SquarePants, he's the co-star of SpongeBob's favorite show, Mermaid Man and Barnacle Boy. He voiced Barnacle Boy, and - bonus for fans of McHale's Navy - Ernest Borgnine voiced Mermaid Man. In the show, they featured in 12 episodes as semi-retired superheroes who SpongeBob discovers live right there in his hometown. They're a spoof of Batman and Robin, and other superhero duos, which brings us to the next pair of classic TV stars...

2

Adam West and Burt Ward as Young Mermaid Man and Young Barnacle Boy

For the episode "Back to the Past/The Bad Guy Club for Villains," SpongeBob goes back in time to visit his favorite superheroes. To voice the younger versions of the show's iconic duo, they brought in Batman's Adam West and Burt Ward. (Bet you never thought you'd see a Robin with fins!)

3

Marion Ross as Grandma SquarePants

On Happy Days, Marion Ross played Mrs. C, Richie's mom, but on SpongeBob SquarePants, those sweet maternal instincts came in handy when she was asked to voice the character of SpongeBob's grandmother. In her debut episode, the premise finds SpongeBob embarrassed by his grandma's kisses in public. We bet Richie and Joanie can relate!

4

Henry Winkler as Sharkface

Marion Ross isn't the only familiar face from Happy Days we saw rock Bikini Bottom. Henry Winkler made the jump to voice a character in the animated series when he showed up as Sharkface, the leader of a tough gang called "The Sharks." And who should they cast for his goons? Funny you should ask...

5

David Lander and Michael McKean as Donnie and Lonnie

To round out the goons in Fonzie's underwater shark gang, SpongeBob SquarePants got Lenny and Squiggy from Happy Days spin-off Laverne & Shirley. They played Donnie and Lonnie, and SpongeBob veteran voice actor Clancy Brown (Mr. Krabs) voiced the third shark gang member Ronnie.

6

Pat Morita as Master Udon

Rounding out our Happy Days alum on SpongeBob SquarePants, Pat Morita (Arnold!) voiced the character Master Udon in the episode "Whale of a Birthday/Karate Island." He played a conniving green fish who tricks SpongeBob into coming to his island and kidnapped Sandy. When his plots are foiled, Sandy was known to shout, "You're in the soup now, Udon!"

7

Michael McKean as Captain FrostyMug

We'd be remiss not to discuss the other time Michael McKean lent his talents to SpongeBob. For his debut voicework, he played the character Captain FrostyMug, the instructor at the milkshake academy where SpongeBob goes to renew his license. The character had a delightful dual nature where he was strict and stern during class but warmed up to a friendly force after class was dismissed.

8

Betty White as Beatrice

At the Bikini Bottom Mall, you can find Betty White voicing the character Beatrice, who owns the shop Grandma's Apron. She's a sincerely sweet old lady, but watch out! She has "Granny Powers!"

9

Ed Asner as Angry Old Timer

On The Mary Tyler Moore Show and Lou Grant, Ed Asner played a bit of a grump, but on SpongeBob SquarePants, he took it to the max with his Angry Old Timer. Carrying a cane, he actually steals from SpongeBob and Patrick, but in the end they realize why he stole, and the cartoon stars help him realize his dream. Who lights the underwater world up with his smile? Sing it if you know it: SpongeBob SquarePants, SpongeBob SquarePants, SpongeBob SquarePaaaants!

10

Davy Jones as Himself

On SpongeBob SquarePants, there's an ongoing joke about "Davy Jones' locker" and with a little help from wordplay, that led to a live action cameo of The Monkees' Davy Jones on the show. He sang a great rendition of "Daydream Believer" to the sunken locker full of dirty socks.

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See also: The voices of The Smurfs turned up all over classic television

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