- Voiced By: Will Smith
Oscar was the son of Earl who was a tongue scrubber at the Whale Wash of Southside Reef. Oscar wanted to live at the top of the reef someday.
- Butt-Monkey: He gets no respect for working at the car wash, he was shown being bullied as a child in a flashback, and he ends up getting slammed across a wall repeatedly by Lola. Even while famous, he was belittled and abused by Lola and used for his wealth and fame by Sykes.
- Didn't Think This Through: Takes credit for killing a shark without realizing the following. 1) People would expect him to fight sharks from now on. 2) Said shark likely has family and friends who won't take kindly to his death. 3) He is clearly not a fighter.
- Extreme Doormat: Is beaten, assaulted, and mistreated by Lola, yet he never objects or protests in any way besides breaking up with her, though him breaking up with her is completely unrelated to her prior abuse of him.
- Fake Ultimate Hero: Oscar decided to become the "Shark Slayer".
- Flanderization: In the PC version of the video game, Oscars even worse. He doesnt pay his rent for three months because he is too lazy and cheap. Its even worse because one of the missions in the game actually revolves around you getting him to the racetrack in time to bet Sykes money.
- Friend or Idol Decision: Eventually, Oscar had to choose between continuing his facade or his true friend Angie. He picks the latter.
- Heterosexual Life-Partners: With Lenny.
- Idiot Hero: He makes some pretty dumb decisions. For example, Angie gives him a pearl that he can use to get out of his debt - and he instead bets it at the seahorse races.
- I Just Want to Be Special: He wants to be rich and famous, but his get-rich-quick schemes landed him in debt. Seeing that Ernie and Bernie think he killed a shark, he takes advantage of this.
- Informed Species: He's supposed to be a cleaner wrasse, but he doesn't look like one. Or any sort of fish at all, for that matter. Truth be told, he just looks like a miscolored Will Smith with a tailfin.
- Jerk with a Heart of Gold: Oscar comes off as brash and makes impulsive and selfish decisions, but he's a Nice Guy who will do anything for his friends.
- Leitmotif: His leitmotif is rap music.
- Like Father, Like Son: Oscar follows his dad's legacy at the Whale Wash.
- Love Revelation Epiphany: After Angie admits she did love Oscar before he let his success go to his head, Oscar spends the rest of the night depressed. When Lola mocks her admission and asks if he even has feelings for her, Oscar realizes that he does indeed love Angie.
- No Respect Guy: At the whale wash, only Angie seems to respect him. After becoming the Sharkslayer, Lola enters a relationship with him and shows him absolutely no real respect, instead belittling and mistreating him.
- Oblivious to Love: He was unaware that Angie was in love with him. That is, until she said something.
- Talking Jive: "OLD SCHOOL!"
- Wouldn't Hit a Girl: Oscar never attempts to defend himself in any way when Lola slams him against a giant lava lamp, forcefully makes out with him in public, or assaults and beats him for ending their relationship.
- Voiced By: Jack Black
Lenny was the second son of Don Lino who prefers to eat vegetables. He is more kind and caring than Frankie.
- Ambiguous Disorder: Lenny is likely to have autism due to how he processes life around him.
- Ambiguously Gay: Lenny has a feminine voice and acts differently.
- Big NO: Lenny yelled one after the death of his brother.
- Cloudcuckoolander: The only shark to be considered this way.
- Gentle Giant: He's a great white, but he would rather be friends with fish than eat them.
- Heterosexual Life-Partners: With Oscar, though the "hetrosexual" part is a little shaky.
- Nice Guy: Lenny's a friendly guy and seems to be one of the only sharks not willing to eat fish.
- Like Father, Unlike Son: Lenny wants to be himself rather than just be a shark like Lino or Frankie.
- Shipper on Deck: He's ecstatic when Oscar decides to tell Angie he loves her.
- White Sheep: He's the only shark who doesn't want to be a carnivore and wants to get along with fish.
- Voiced By: Renée Zellweger
Angie is a receptionist at the Whale Wash. She is good friends with Oscar.
- Anguished Declaration of Love: She makes one when Oscar rants about how his life wasn't special until he became the "Shark Slayer".
- Betty and Veronica: The Betty to Lola's Veronica. Angie wins.
- Cannot Spit It Out: She's in love with Oscar, but she can't admit it. When she does, it's at a point wherein she realizes he's a jerk.
- Concert Kiss: Gives Oscar one after he rescues her from the sharks and brings peace to the reef. Though the way she does it is very similar to Lola's earlier forced make-out session, she does it to actually express her love for Oscar, unlike Lola who did it as a stunt to show off her relationship status with Oscar.
- Damsel in Distress: She gets kidnapped by Don Lino in order to lure Oscar.
- Foil: To Lola. Both want Oscar's affections and end up forcefully kissing him in public. However, Angie has known Oscar for some time and cares about him for his character, whereas Lola seduced him immediately after meeting her and is only interested in his wealth and fame.
- Forced Kiss: After forgiving Oscar for his lie, she lunges at him and catches him off-guard with a kiss. The kiss is much more loving than Lola's earlier forced kiss, in which she pinned him under her and maintained complete control of the make-out session.
- Love Doodles: Her Establishing Character Moment is her doodling her love for Oscar.
- Nice Girl: Angie is very friendly towards others, so friendly that she offered her grandmother's pearl to Oscar to help him pay off his debt.
- Smooch of Victory: Gives one to Oscar after he rescues her from the sharks and brings peace to the reef. While the kiss is forced onto him just like Lola's earlier public make-out, it is clearly filled with passion and love.
- "The Reason You Suck" Speech: Angie gave one to Oscar after he became a bigshot.
- Tsundere: Angie acts like a Type-B one towards Oscar, considering how she has a crush on him.
- Voiced By: Martin Scorsese
Sykes is the owner of the Whale Wash. He is secretly a loan shark to Don Lino.
- Voiced By: Robert De Niro
Don Lino is the head of his great white shark gang. He cares a lot about his two sons, Frankie and Lenny.
- Adult Fear: After Frankie's apparent murder - left unpunished and the killer publically rewarded, mind you - and funeral, Lenny - whom he probably considered more helpless and vulnerable - ran away and reappared only to get slaughtered by the very fish responsible for Frankie's death. Anyone would be out for blood following that.
- Big Bad: After Oscar told the lie, Lino became the Big Bad.
- Even Evil Has Loved Ones: He greatly cares for his sons, though is upset with Lenny being a vegetarian.
- Jerk with a Heart of Gold: He comes off as this at the end when he learns to accept Lenny for who he is and stops being hostile towards Oscar and the fishes.
- Love Redeems: After realizing Oscar's truth on the death of Frankie, he and the sharks are not enemies.
- Parents as People: He genuinely cares for Lenny but can't see or accept the fact his son will never be a "typical" shark. He comes around at the end.
- Voiced By: Angelina Jolie
Lola is a lionfish who is very provocative and is attracted to fish who are rich.
- Aroused by Their Voice: Her voice fits perfectly for Angelina Jolie.
- Bastard Girlfriend: Abuses and humiliates Oscar during their short-lived relationship in a variety of ways, and is only interested in his wealth and fame.
- Betty and Veronica: The Veronica to Angie's Betty.
- Bitch in Sheep's Clothing: She tries to pass herself off as being a decent person deep down, but it's all an act.
- Bright Is Not Good: Lola dresses in a very flashy and colorful way, and is a manipulative and abusive gold digger.
- Card-Carrying Villain: She outright calls herself "really superficial" to Oscar's face in her very first scene.
- Concert Kiss: After Oscar pretends to defeat Lenny, the thousands of celebrating onlookers are treated to the sight of Lola pinning Oscar down and making out with him.
- Death Glare: Lola gave a frightening one to Oscar after he dumped her, right before savagely and mercilessly beating him against a glass window in public.
- Destructive Romance: Lola's short-lived relationship with Oscar consists largely of Lola abusing, assaulting, and belittling Oscar, while he passively accepts this blatant mistreatment.
- Disproportionate Retribution: Oscar dumps Lola. Lola brutally beats him against a glass window in plain view of dozens of people, who laugh as he suffers.
- Double Standard: Abuse, Female on Male: She viciously beats up Oscar after he dumps her in plain view of 20 or 30 other fish, but nobody tries to stop her. Sykes even jokingly calls this "young love."
- Entitled to Have You: When she discovers Oscar is rich and she starts dating him, she ends up getting angry and beating him up when Oscar dumps him. So basically, she felt that she should have been the only one Oscar should be dating.
- Establishing Character Moment: She appears to the song "Gold Digger" and flirts with Oscar after he places his bet, but leaves and calls him a nobody after learning he isn't rich.
- Everything's Better with Spinning: She is fond of spinning Oscar around while being seductive. She uses one hand on his hand to give him a quick spin when they reunite at Oscar's penthouse, and she does it again immediately before grabbing and making-out with him. She also spins herself while dancing for Oscar the first time they meet, and spins herself and Oscar while beating him up after being dumped.
- Excessive Evil Eyeshadow: Wears an unnecessarily heavy amount of purple eyeshadow ar t all times.
- Extreme Mêlée Revenge: After getting dumped, she beats Oscar by repeatedly slamming him against a glass window with full force. Judging by his pained expression and how he slides down to the floor with his face covered in his own spit, coupled with the loud thudding of his face against the glass, it was certainly brutal.
- Foil: To Angie. Both want Oscar's affections and end up forcefully kissing him in public. However, Angie has known Oscar for some time and cares about him for his character, whereas Lola seduced him immediately after the two met and is only interested in his wealth and fame.
- Forceful Kiss: After Oscar's staged fight with Lenny, Lola sneaks up on Oscar in front of the cameras and sweeps him into a passionate make-out session for the whole town to see. Oscar seems surprised by this at first but then seems to accept and return the kiss. Lola keeps him pinned under her and maintains complete control of the kiss, which reflects her domineering and abusive nature.
- Gold Digger: Bonus points for the song that plays during her first appearance.
- Hoist Hero over Head: Does this to Oscar during her violent beating of him after he dumps her.
- Human Hammer-Throw: Does this to Oscar against a glass window during his beating at her hands.
- Informed Species: Due to the animation clearly trying to make her look like Angelina Jolie, she looks nothing like an actual lionfish.
- Jerkass: Lola is revealed to be this in the climax of the film after she gets dumped by Oscar and has Angie kidnapped for revenge. In addition, immediately after being dumped, she cruelly beats Oscar.
- Lady in Red: Lola has red "hair", a red "dress", and red lipstick.
- Make-Up Is Evil: Wears the heaviest makeup of any character in the film by far and is undeniably wicked.
- No-Holds-Barred Beatdown: Shows Oscar no mercy as she savagely beats him.
- No Sense of Personal Space: She has a tendency to get far too close to Oscar, even when he is clearly uncomfortable. Examples include when she roughly slams him against a giant lava lamp and caresses his body and face while her face is uncomfortably close to his, forcefully grabs and kisses him in public, and wraps one arm around him and pushes his face closer to hers with the other hand while he is clearly upset and uninterested.
- Not Good with Rejection: After Oscar breaks up with her as gently as he can, she responds by giving him a frightening Death Glare, savagely slamming him against a glass window repeatedly in front of dozens of people, and ratting him and Angie out to the sharks.
- Revenge: The only thing she loves more than money. After Oscar dumps her she gets her immediate revenge by beating and humiliating him, and later on by ratting him out to the sharks.
- Rich Bitch: Lola considers fish that are poor to be nobodies. When one "nobody" she belittled and disrespected suddenly becomes a "somebody", she feels entitled to have him.
- Sexual Karma: Implied by the mid-credits scene.
- Smooch of Victory: After Oscar's staged battle with Lenny, Lola decides to "reward" him by sneaking up on him, pinning him under her, and forcefully making out with him in front of thousands of onlookers. He seems to enjoy and accept her reward after his initial reaction of shock and surprise.
- Stealth Pun: She's a lionfish, a species of fish known for its venomous spines, who is also an abusive love interest to Oscar. She and Oscar are in a toxic relationship.
- The Vamp: Lola uses her beauty and provocative actions (dancing, touching, making out) to seduce Oscar.
- Waif-Fu: She demonstrates incredible strength when she effortlessly and brutally beats Oscar.
- Woman Scorned: Lola's immediate reaction to being politely dumped by Oscar privately is to mercilessly beat him against a glass window in front of dozens of people.
Ernie and Bernie
- Voiced By: Ziggy Marley (Ernie) Doug E. Doug (Bernie)
Ernie and Bernie are two Jamaican jellyfish who love to have fun and sting anybody who is mean to them.
- Electric Jellyfish: The two even made a joke about their stinging.
- The Dragon: Serves this way to Sykes.
- Those Two Guys: They are always seen together and are likely brothers.
- Voiced By: Michael Imperioli
Frankie is the first born son of Don Lino and Lenny's older brother. He was later killed by an anchor.
- Cain and Abel: Frankie is considered Cain and Lenny is considered Abel. However, Cain dies.
- Famous Last Words: "Moron." in response to Lenny.
- I'm Cold... So Cold...: Lenny replies, "That's because we're cold blooded." Frankie hits Lenny and replies back, "Moron".
- Sibling Rivalry: Frankie's aggressiveness makes Lenny feel quite uncomfortable.
- Small Role, Big Impact: Frankie's death started the conflict and the Shark Slayer story.