Frank the Muscular Goldfish is a muscular goldfish, usually seen exercising at Goo Lagoon. His first appearance was in MuscleBob BuffPants. His name was revealed in Slide Whistle Stooges. Sometimes he dines at the Krusty Krab such as in To Love a Patty.
Frank is very muscular. His color is almost a bronze-brown color, and he wears a black speedo. He has a fin on his back, and has black eyes.
- In Slide Whistle Stooges, Nancy was his girlfriend.
- In Pre-Hibernation Week and The Fry Cook Games, Frank had a small, light voice. But in Slide Whistle Stooges he had a deep, tough voice.
- Frank the muscular goldfish is not to be confused with the store owner Frank, the jail guard Frank, and the cameo character Frank.
- His name is revealed in Slide Whistle Stooges.
- In The Krabby Kronicle there is a fish that's called Trainer that looks like Frank.
- Despite being very muscular, he apparently has a weak constitution.
- In Ripped Pants and MuscleBob BuffPants he is exercising, but in the other episodes he is not.
- "I gotta get outta here!"
- "Who would do such a thing?"
- "Gold Team rules!"
- "Remember to take plenty of fluids."
- "This is weird."