Unknown and Unnamed Characters
There are many Bikini Bottomites that are yet to be named.
Large orange fish with green fins —There were multiples of these in Sandy, SpongeBob, and the Worm, Krusty Krushers, and The Fry Cook Games. He might have been affected by the Alaskan Bull Worm. he came to the Krusty Krab, when it was the Kuddly Krab.
Blue fish with purple stripes —Mr. Krabs dropped a penny and once he picked it up Mr. Krabs says "YOUR LUCK JUST RAN OUT". He explains to Patrick, that Chocolate leads to Fat in Chocolate With Nuts. He Suggested they go to the Chum Coliseum, in Spongicus.
Blue fish with lavender chest —He is a Major Cameo character. He Has a Kid Look--alike, and he has been to Inferno Island
Old orange fish —in The Bully when SpongeBob ran through town screaming "HE'S GOING TO KICK MY BUTT!" they mistaken the old man for saying that he was going to kick his butt. He presumably lives in Shady Shoals Retirement Home. He was affected by the "Ghosts" in Pranks a Lot. However its is revealed to be another Old Man Jenkins but if thats true the unknown and unamed character case for him is solved.
Teenaged Squid —She liked the Krusty Krab when Pearl turned it into the The Kuddly Krab. She was in Squidward's band in Band Geeks. She was in the Group with Squilliam Fancyson. She is a friend of Pearl's friends. She attends Mrs. Puff's Boating School.
Blue fish with dark blue stripes—He says Patrick was trying to kill him in Something Smells, in Krabs a la Mode He says "I want patty skates too!" Referring to how SpongeBob was serving food. He was a cowboy in F.U.N. He is probably friends with SpongeBob.
Blue fish with purple dress —in "Krabs a' la Mode" she wanted 2 frozen Krabby Patties. She attended Squidward's Party for being Employee of the Month. She asks SpongeBob if he was "Trying to keep in style" referring to Ned's Wig, in Wigstruck.
Large Old Fish —Mr. Krabs was trying to not have to put SpongeBob in charge of the Krusty Krab in Gullible Pants, and states that this guy was "Too Lumpy". He asked Old Man Jenkins, what Mr. Krabs' problem was in Mid-Life Crustacean.
Brown fish with purple shirt —in Wigstruck he asks SpongeBob "Off to Meet the Queen, Sir Nerdlaroy?". And in Spongicus he is scared Plankton is going to destroy the Krusty Krab and puts his chair on his head.
Grey fish with pink shirt —is possibly married or dating the blue fish with purple stripes. She is possibly the Saleslady, or is a relative. she has been to Bass Vegas, with Fred. She is a very common cameo. She is the fish that pointed out that SpongeBob was not wearing his name tag.
Pet Show Judge —Looks exactly like Thaddeus, but is a different color. He judges the Annual Pet Show.
License award Announcer —He congratulated Patrick for being the 1,000,000th person to pass the Boating Test, in Driven to Tears.
Referee He Called SpongeBob and Patrick "Fresh Meat" in Krusty Krushers
Brown shaded fish —He tells Frank (Muscular Goldfish) That Squidward was causing destruction in Bikini Bottom in Slide Whistle Stooges. he was the First fish to hear, I Wrote This. He felt off balance after being bitten by Gary.
Blue fish with red outfit —Some indicate that her name is actually Nazz, but that is not proven, yet. She is the sister of Sadie Rechid. she said Squidward, hurt SpongeBob's feelings in Giant Squidward, Shubie may be her Friend.
Narrow lavender fish -—Seen in some episodes as a cameo character. May date Tina.
Boy Scout -—Seen in Mid-Life Crustacean.
Orange Fish —He has never played a role in any show and appears in some Episodes as Cameo.
Green and Blue Fish —He is a Common Cameo, He attends Mrs. Puff's Boating School. He has a Larger Look--Alike that plays for the Local Hockey Team.
Black Fish —Cameo Character, and also the Fish Who opened the Door so Mr. Krabs could throw Plankton out.
Orange —He is an Orange Fish. He is seen in about 20-40 Episodes. he eats at the Krusty Krab. Mr. Krabs had the Idea to put him in charge of the Krusty Krab while he Was gone in Gullible Pants. he wears a Black Hat.
Grey Fish with Green Trunks —He was on T.V saying hey to All of his Friends. He has a Kid Lookalike. He Also hates I Wrote This.
Surfer —He is a major Cameo. He hangs out with Scooter. He enjoys Goo Lagoon. He was the guy that says SpongeBob was the wizard who saved the Bikini Bottomites from being minions of Planktopolis. He tells SpongeBob off in Stuck in the Wringer.
 Store Owners
Mattress Salesman —Sold SpongeBob a new mattress in The Lost Mattress.
Pinchers Vendor supplies Salesman —Brought Mr. Krabs his machine in Skill Crane
 Unnamed Staff
Shady Shoals Headmaster —Appeared in Doing Time and Mermaid Man and Barnacle Boy.
Jellyfish Feilds Ranger —Appeared in SpongeBob's Last Stand.
Pharamedics —are Actually Joes that are in multiples.
Nurse —She appeared in the Lost mattress, not to be confused with Nurse Sadie Rechid.
 Pearls Friends
Green Thug -—A thug that is obviously friends with Reg. Because he treats the Green thug like a regular at the Salty Spitoon,he can make his tattoo of a SeaHorse Wiggle and When SpongeBob was trying to get into the Salty Spitoon he impersonated as a Tattoo. He appeared in the Tough Tavern, in SpongeBob meets the Strangler.
Orange Thug He appeared in the Krusty Krushers (First in line to face the Champions) and he also appeared in the episode SpongeBob's Last stand.
Thugs from the Thug Tug —These include large and Muscular Goons,the Owner, also a Dj, and A "Two Headed Bubble Blowing Baby", (Spongebob Squarepants the Movie]].
 Vagely--Known Characters
Thaddeus —he is a Green Fish that wears a Orange Shirt. He was asked by SpongeBob if he was a Robot.
Jess,Ivy,Pilar,Mable,Mevis —Names heard in Good Ol' Whatshisname.
Medley —is a green fish. name was revealed in Hall Monitor. is the husband of Beth.
Mrs. Krabs —is presumably a whale and is the wife of Mr. Krabs.
Martha Smith —She is the wife of Harold, and in the episode SquidBob TentaclePants, she gave birth and was shocked to see SpongeBob/Squidward. She scolded Mr. Krabs for wanting to pick up a quarter that Tyler had dropped. She scolded him again in The Krabby Kronicle, for supposedly over working SpongeBob.