Main Characters: SpongeBob SquarePants | Patrick Star | Squidward Tentacles | Mr. Krabs | Sheldon Plankton
Recurring Characters | Minor Characters | Movie Characters | Video Game Characters
- Cash Gate: In Goo Lagoon, he serves as an order placer for shipments and asks for 300 sand dollars to allow SpongeBob access to the pier.
- Fetch Quest: He sponsors the jellyfishing competition in Jellyfish Fields and requires 100 total jellyfish in order for SpongeBob to gain access to his Reef Blower 2500 inside his corral.
- New Job as the Plot Demands: He's introduced as the owner of the Bait Shop in Jellyfish Fields, but once SpongeBob wins his jellyfishing competition, he's seen again in Goo Lagoon as an order placer for shipments. Later zig-zagged, as he returns to his job as the Bait Shop owner once the pier is destroyed.
- Screw This, I'm Outta Here!: Once the pier in Goo Lagoon is destroyed by the Flying Ducthman, he remarks that he has nothing to do there anymore and returns to his previous job in Jellyfish Fields.
- What the Hell, Hero?: When SpongeBob wins the Reef Blower 2500 and he tests it out, he ends up scaring away all of Rusty's snails from his corral and he calls him out on it. He later tells SpongeBob to try it on in his changing tent for safety reasons.
- Disproportionate Retribution: His main reason for ending up as Mermaid Man's worst enemy is because he put a red sock in Mermaid Man's laundry and turned all of his clothes pink.
- Easter Egg: Prawn makes a brief cameo in the Mermalair level in SpongeBob's Truth or Square where SpongeBob will mistake him for Man Ray at first before saying he's an unassuming shrimp.
- Flunky Boss: Prawn starts spawning Ham-mer robots into the fight once he takes one hit.
- Achilles' Heel: The robot's loose head is her weak point which is prone to being knocked off by SpongeBob and Patrick's Ground Pound attacks.
- Evil Knockoff: She is a giant robot based off Sandy Cheeks.
- Giant Space Flea from Nowhere: Robo-Sandy doesn't have any relevance to the plot of the game and only shows up as the first of the major three robot bosses to fight.
- Shockwave Stomp: Her elbow slam attack produces a shockwave that spreads across the floor of the arena.
- The Voiceless: Robo-Sandy is the only robot boss to not be voiced.
- Achilles' Heel: The "Kick me!" sign on his back, which according to SpongeBob, hides a self-destruct button.
- An Ice Person: One of his attacks is an ice breath which he uses to freeze Squidward and SpongeBob over the course of the fight.
- Ax-Crazy: Robo-Patrick is the most unhinged of the three robot bosses as he wants to eat Squidward (and SpongeBob) for dessert.
- Defeat Equals Explosion: After SpongeBob lands the final blow, he screams in pain and explodes.
- Eating Machine: He constantly eats ice cream made out toxic sludge and wants to do the same to a helplessly frozen Squidward.
- Evil Knockoff: He is a giant robot based off Patrick Star.
- Giant Space Flea from Nowhere: Like with Robo-Sandy, Robo-Patrick has little relevance to the main plot and only appears as a boss.
- Spin Attack: His "do sa do" attack is a continuous spin where he'll spray toxic ice cream in every direction. The attack leaves Robo-Patrick dizzy for a short while after use.
- Achilles' Heel: SpongeBot has numerous exposed lights all over his body which are prime targets for SpongeBob's Cruise Bubble.
- Dual Boss: In the first phase, he is fought alongside Robo-Plankton.
- Evil Knockoff: He is a giant robot based off SpongeBob SquarePants.
- Expy: SpongeBot SteelPants is a larger version of the SpongeBob robot that Plankton built in Welcome to the Chum Bucket, which came out a year before the game's release.
- Final Boss: He is the last major robot boss in the game that SpongeBob has to fight to end the robot invasion.
- Level in Boss Clothing: His second phase is a platforming gauntlet inside his body where SpongeBob must destroy the fuses to deactivate him.
- Weapons-Grade Vocabulary: His "Kah-Rah-Tae" attack weaponizes each syllable of the word and fires them at the platforms SpongeBob is standing on.
- Big Bad: He usurps this role from Plankton himself and becomes the main villain at the end of the game.
- Battle Couple: Assists SpongeBot in his first boss fight and they are apprently engaged.
- Camp Gay: Played for Laughs. Robo-Plankton talks about marrying SpongeBot SteelPants and retains all of regular Plankton's campiness and theatricality.
- Dual Boss: In the first phase, he is fought alongside SpongeBot SteelPants.
- Energy Weapon: His hovercraft is equipped with a rapid-firing laser weapon.
- Evil Knockoff: Eviler knockoff; he is a giant robot based off the already-evil Plankton who takes over as the Big Bad of Battle for Bikini Bottom.
- Final Boss: In the second phase, he goes inside SpongeBot SteelPants and becomes the last enemy to intercept SpongeBob as he tries to destroy the fuses.
- Off Screen Karma: After you beat SpongeBot, the Dupilcatotron 3000 begins spitting out clones of him at a rapid pace that all shout that they want to destroy each other. Presumably, they all do so offscreen, including the original model.
- Promoted to Playable: Is promoted to a playable character in Rehydrated's Horde Mode.
- Prima Donna Director: While he may seem affable on the surface, Gill is a perfectionist and will get temperamental if his quota isn't met. He'll even outright demand the participants to redo the audition minigames from scratch if they fail to reach the point threshold needed for the role.
The Sneaky Hermit
- Big Bad: He's the main villain of the game's Show Within a Show who wants to steal every home in Bikini Bottom.
- Freudian Excuse: The reason he wants to steal every building is because his ex-wife took the house in their divorce, leaving him without a home and turning him to villainy as a result.
- Static Role, Exchangeable Character: The Sneaky Hermit can be played by any of the six main characters if they accumulate enough total audition points and beat the rest of the competition by the end of the story campaign. As a result, the Sneaky Hermit's personality can vary drastically, ranging from SpongeBob's goofiness to Plankton's melodrama.
- Weaksauce Weakness: His nose is very sensitive to peppers. Mermaid Man and Barnacle Boy defeat the Sneaky Hermit this way by spraying pepper on him and making him sneeze, causing him to drop all of his stolen buildings back into their original spots.
- Arc Villain: He serves as the main villain in "Starfishman to the Rescue".
- The Bad Guy Wins: While more Played for Laughs, at the end of the level, Dreaded Patrick successfully baits Starfishman to the rocket, have his minions knock him out, performs the old switcheroo with the hostage and launches Starfishman into space. This is even lampshaded by both Starfishman (who notes that The Good Guys Always Win), and Dreaded Patrick himself (who is forced into a And Then What? situation about what to do next). As a Double Subversion, Dreaded Patrick still gets some karmic retribution in the end as a doughnut-shaped meteor the rocket hits on its way out falls to Earth and traps him in it.
- Evil Counterpart: He's essentially just an evil version of Patrick in a world full of starfish citizens who look and sound like him.
- Large Ham: Even by Bill Fagerbakke's standards, Dreaded Patrick speaks entirely in a deep, overly-hammy voice to emphasize his role as a supervillain.
- Non-Action Big Bad: He spends the entirety of the level taunting and making threats to Starfishman, but doesn't really get involved with him directly and prefers his minions to do the dirty work. The only things he does directly are plaster propaganda posters all over Bikini Bottom, tie up a starfish citizen to be run over by a train, and take another starfish citizen hostage in his lair to bait Starfishman to the rocket.
- The Unfought: Dreaded Patrick is never fought directly. The "final showdown" Starfishman has with him is just an Elevator Action Sequence where he fights hordes of his minions and dodges incoming hazards instead.
The Village Chief
- Companion Cube: The Chief has an ironing board for a wife, of whom he sees as "pretty pretty". It later gets subverted when SpongeBob rescues "her" and the Chief realizes that he doesn't find her pretty pretty anymore, and so he insists SpongeBob to take the ironing board with him as a useful plane part.
- Large and in Charge: He's the biggest and most top-heavy member of the castaways, which signifies his position as the village chief.
- Creepy Good: Despite the Inventor's awkward mannerisms and implications that he desperately wants SpongeBob as his lab assistant/test subject, he's an otherwise nice guy who will give SpongeBob helpful hints on his journey and provides him with another plane part in return.
- Fetch Quest: His primary task for SpongeBob is for him to take back the three jellyfish power cells, which were stolen by the worm crustaceans and locked deep inside his three workshops.
- Gadgeteer Genius: He's the inventor of the jellyfish-powered device that makes him the perfect cup of tea. Some of his other inventions mentioned in his dialogue also include "a telephone", a seismic back scrubber and a pair of untested rocket pants.
- Mission Control: He provides SpongeBob with hints from his lab as he searches through the Inventor's workshops for his jellyfish power cells.
The Mutant Krabby Patty
- Advancing Boss of Doom: It serves as a major enemy that Plankton must run away from in "Super-Sized Patty".
- Antagonist Title: It's the titular Creature from the Krusty Krab, as well as the Big Bad of the game.
- Big Bad: It is ultimately revealed to be the one behind the string of nightmares in the game, with said nightmares actually belonging to Gary the Snail.
- Outside-Context Problem: At first glance, the Mutant Krabby Patty appears to be just a mindless monster that Plankton accidentally created from a lab accident. But towards the end of the game, it reveals its true nature to be the embodiment of SpongeBob, Patrick and Plankton's nightmares, with the final level being dedicated to chasing after it in hopes of ending the whole thing.
- Super-Persistent Predator: After coming to life, it becomes entirely fixated on chasing after Plankton for seemingly no reason, with most of the destruction it causes in Bikini Bottom being collateral.
- Walking Spoiler: It plays a much larger role in Creature from the Krusty Krab and carries a revelation that is saved for the final level.
- Your Size May Vary: In "Super-Sized Patty", the Mutant Krabby Patty is three times the size of the average Bikini Bottom citizen and can easily crush objects in its path. But later in the game, it oddly becomes the same size as SpongeBob as it is able to latch on to his plane without dwarfing it.
SpongeBob's Boating Bash
- Big Bad: It is revealed that he has been manipulating SpongeBob for the whole game all for the sake of money.
- Bitch in Sheep's Clothing: Initially appears to be a kindly old boating instructor, but only cares about taking SpongeBob's money by tricking him into joining his sham classes.
- Broken Pedestal: SpongeBob is utterly broken upon learning Seymour's true intentions.
- Con Man: His entire class is nothing but a grand scam to get a rather gullible SpongeBob to pay more money. Some of the other characters like Mr. Krabs and Mrs. Puff were quick to figure this out, but the reason they fail to tell SpongeBob early is because the former is swayed by money talk, while the latter goes incognito to investigate the whole thing.
- Cool Car: Or boat, in this case: his Big Tug tugboat towers over any other boat in the game and has a giant open shark mouth painted on the front.
- Defeat Means Playable: Is unlocked as a playable character following his defeat in the story mode. You also unlock his Big Tug as well, not to mention the Small Tug you use in his boss fight.
- Final Boss: Once Mrs. Puff reveals to SpongeBob that his license is a fraud, Seymour becomes the last boss of the game.
- "Get Back Here!" Boss: The boss fight with Seymour is a chase sequence where SpongeBob must destroy his boat before he gets away. There's a meter on the right side of the screen which shows the distance between Seymour and SpongeBob. If the icon indicating Seymour hits the very top of the meter, it's game over. To make it harder, Seymour will toss junk out of his boat to slow SpongeBob down.
- Insane Troll Logic: He tells SpongeBob at the beginning that his idea of becoming a better driver is to become a reckless one. This is perhaps deliberate as he wants nothing more than money from SpongeBob anyway.
- Loan Shark: A literal one: he offers SpongeBob boating classes at extortionate prices and has the sponge and his friends pay for them by selling the parts generated from their boating derbies.
- Walking Spoiler: His presence throughout the whole game as a benevolent boating instructor isn't as clear cut as the game makes him out to be, and his true intentions aren't revealed until the very end.