Frank is a brown fish that is a citizen of Bikini Bottom wearing a red shirt. His name is mentioned in Hall Monitor, but his real debut is shown in Valentine's Day. His name was finally revealed in " Krusty Dogs."
Trivia Throughout the series, Frank is constantly ripped off or scammed out of money, possibly a running gag in the show.
In Bucket Sweet Bucket, he complained about the new price of twenty-five dollars for a Krabby Patty but decided to buy four anyway when he liked the new decor.
During the episode, Krusty Kid's Meal, he was going to buy the new kids meal for just two dollars only to get Mr. Krabs to double it.
In The Clash of Triton, Bikini Bottomites were going to watch King Neptune eat for five dollars, but Krabs didn't want to give change for a twenty.
In Kracked Krabs, there was a video showing Frank being ripped off by getting charged three times for a bag of chips with triple flavor.
In Chum Bucket Supreme when he is approaching the register at the Chum Bucket, his shirt was red. At the next shot, the shirt is blue.
In Once Bitten, despite that he was bitten, he somehow managed to survive the infection (or thinking he was infected) therefore he never became a zombie. He was able to stand upright as well. He is seen in the mob of survivors that are using the Krusty Krab as a safe zone.