Oscar is the main character of Shark Tale. He is Angie's boyfriend and co-worker, Lenny's best friend, Lola's ex-boyfriend and the former tongue-scrubber and current co-manager of the Whale Wash. He is a blue-streaked cleaner wrasse.
Oscar is a professional tongue scrubber at his job the Whale Wash who doesn't seem to get much respect, and seeming to get himself into unwanted situations. In his youth, he admired his dad Earl's work at the Wash so much he decided to bring it to school for show and tell, only for the class to cruelly mock him. This tragic disaster caused Oscar to consider himself a loser and a "nobody". Since then, Oscar dreams to be rich and famous and to be a respected somebody.
Arriving late for work one day, Oscar finds that he's already punched in on the time clock, and realizes he has been helped out by Angie, the angelfish receptionist and cashier at the Whale Wash (and harbors a secret unconditional crush on him). He stops by her office to thank her and chat, and exasperates her with his latest get-rich-quick-scheme: bottled water. Angie advises Oscar to just do his job "which, by some miracle, you still have." And Oscar leaves the reception booth.
As the day progresses, Oscar bemoans his existence shoveling slime in the gaping maw of an endless line of whales. A prank turns unpleasant when a whale is accidentally hit in the eye with a jet of soap and thrashes about in pain. Oscar closes the emergency clamps to hold the whale immobile and squeegees the soap from the whale's eye, shortly before Syke's jellyfish henchmen Ernie and Bernie arrive and hurl him into Sykes' office. To raise the cash to pay of Don Lino, Sykes demands that Oscar owes him five thousand clams, to be paid back by tomorrow. A shocked Oscar asks how he can possibly come up with that much money with so little time, but Sykes dismisses his worries and tells him to bring it to the racetrack tomorrow, or else. Oscar asks "or else what?" to which Sykes responds "The boys'll explain." As Sykes leaves, Bernie stings Oscar in the eye as a warning.
That evening, Oscar mopes on Angie's balcony as she tends to his swollen eye. She can't understand why Oscar always gets himself into these situations, nor his obsession with trying to live at the top of the reef. Oscar recalls his late father, a tongue-scrubber at the Whale Wash for 25 years and how he admired his work so much he brought it to school, only for the class to cruelly mock him for it. After that, he desperately wanted to be a somebody. Angie tries to explain to him that he doesn't need to live at the top of the reef to be a somebody, and, feeling sorry for him, she tries to help him out by giving him a pink pearl – a precious gift from her grandmother. Oscar is reluctant to take such a valuable object from her, but Angie insists, saying it will get him the money he needs to pay back Sykes.
The next day, Oscar has pawned Angie's pearl and arrives at South Side Racetrack with the 5,000 clams, but becomes distracted in his dreams of fame. Hearing the race is rigged, Oscar instead foolishly bets all of Sykes' money on Lucky Day to win. The boldness of the wager attracts the attention of gold-digging femme-fatale Lola, When Sykes turns up with Ernie and Bernie, he is furious that Oscar has placed a bet with the money he is owed, and Lola, realizing that Oscar isn't the millionaire she imagined, quickly loses interest in him, and dismisses him, calling him a "cute but a nobody." Sykes brings Oscar to watch the race and everything seems smooth sailing and Lucky Day is pulling ahead of the horses, when suddenly the horse trips on the finish line and the race is lost. Oscar sees his dreams of begin rich and famous evaporate, and Sykes, inflating in anger, tells Ernie and Bernie to find the deepest, darkest hole in the ocean.
Ernie and Bernie take Oscar out into the wasteland surrounding the reef, and, with Oscar tied to a rock, torture him with their stingers. At the same time, Frankie and Lenny approach from the direction of Lino's ship. Frankie tells Lenny it doesn't come any easier than this, and instructs him to eat Oscar. Ernie and Bernie flee as Lenny approaches. Lenny psyches himself up to eat Oscar, but can't go through with it, and tries to fake it by biting through Oscar's ropes and thrashing his tail to stir up a cloud of silt to hide Oscar's escape. But Oscar is confused by Lenny's attempt to save him, and is still there, looking baffled, as the silt settles. Furious Frankie tries to attack Oscar himself when suddenly, an anchor falls on top of him, crushing him to death. Lenny swims off distraught, leaving Oscar along with Frankie’s body when Ernie and Bernie return. Realizing he can become famous, Oscar lets them believe he killed the shark.
Oscar returns to the city with a new title of the Sharkslayer. Sykes becomes his manager, Lola becomes his girlfriend, and Oscar moves to the "top of the reef" to live in luxury. When several sharks get close to Oscar's neighborhood, Oscar's neighbors expect him to drive them away. When Oscar runs into Lenny, Lenny (who does not wish to return home) forces Oscar to let him stay with him since he is aware of Oscar's lie. Soon, Angie finds out about the lie, Oscar and Lenny convince her to keep quiet, though she is heartbroken by Oscar's dishonesty.
With Don Lino planning revenge, Oscar and Lenny stage an event in which Lenny pretends to terrorize the town and Oscar must defeat him throwing him into the depths of the ocean. Then Lola forcefully kisses Oscar in front of the cameras causing Angie to leave in anger, jealousy and sadness. Angie furiously argues with Oscar over is lies and fame resulting in her finally confessing that she'd always loved him, "before the money, and before the fame". Angie then tells Oscar that she no longer sees him as a somebody but now a "fake, sham, con and a joke." Oscar, deeply hurt tries to say something, but Angie tells him to go away as she is "tired of hearing about how everything you had in your life wasn't good enough; including me." Oscar sadly swims out of the warehouse, while Angie weeps.
As Oscar sadly swims around the reef, he sees how much his lie has affected him far more than he'd intended it to and what a jerk he has been. He sees the Shorties and Crazy Joe laughing. Oscar remembers how fun the bottom of the reef was like and how he still enjoys it. He then looks at his penthouse and his smile quickly fades. He then sadly enters his penthouse ignoring the party inside and shuts the balcony door behind him. When Lola comes out on the balcony Oscar rethinks his feelings and dumps Lola—which unfortunately, leads to her great fury as she mercilessly whacks Oscar against the windows, before sulking away.
The next day, Oscar buys some Valentine's Day gifts for Angie, but before he can present them to her, he finds that Don Lino has kidnapped Angie to force a sit-down. Lenny comes along now disguised as a dolphin named Sebastian. They arrive at the meeting to find Lola (who obviously arranged the whole thing) next to Don Lino, while Angie is tied up and gagged and presented to Don Lino on a plate who prepares to eat her if Oscar doesn't comply. In response Oscar has Lenny (disguised as a dolphin) to grab Angie and eat her on the spot (grabbing her in her mouth, but not swallowing), but Lenny begins choking and vomits Angie out. Lenny's disgust in fish causes Lino to recognize his youngest son. Lenny in defeat, sheds his dolphin disguise. Lino, however is embarrassed of the situation and accuses Lenny of "taking sides against the family". When Oscar tries to defend Lenny, Lino's sadness quickly turns to fury, and he begins to chase Oscar, snapping his jaws at him.
Oscar leads Lino towards the Whale Wash. He pulls down a lever to trap him into a whale clasping device, only to discover that he trapped Lenny by mistake. Lino continues to chase Oscar. Eventually, Oscar subdues Lino by trapping him into another machinery, leaving him face to face with Lenny.
As a crowd cheers Oscar on, a disappointed Angie begins to leave believing Oscar will continue to live a lie. Oscar can't take it anymore and finally confesses the truth that he lied about being a Sharkslayer, and an anchor killed Frankie. Lino asks Lenny why he never returned home if there never was any Sharkslayer. Lenny responded "You always wanted me to be like Frankie. I'll never be the shark you want me to be." Oscar gives Lino a speech of How everybody accepts Lenny's behavior and why Lino can't do the same. Remorseful, Lino asks Oscar to free him so he can reconcile with Lenny. He then makes a truce with the reef. Angie, amazed that Oscar confessed, forgives him and kisses him. When Katie Current asks Oscar what's next for him after he lost everything he lied about, Oscar looks very thoughtful.
Oscar forsakes all the wealth he has acquired, makes peace with the sharks, becomes co-manager of the Whale Wash (now frequented by sharks, killer whales, and swordfish), and starts dating Angie and enjoys a happy, honest life as he and Angie dance on the Whale Wash sign.
Oscar would prefer to run away from danger rather than fight it. He soon admits that he was a nobody until he lied about killing Frankie and he does the same thing when he confesses that he's not a real sharkslayer.
In Shark Tale, he had no qualms about lying in order to make himself appear more heroic and powerful than he actually and was pretty selfish, arrogant and shallow. Oscar liked to think of himself as a ladies man, but he was somewhat awkward around females, accidentally bumping into a pillar when trying to seduce Lola and stuttering when he tried to tell Angie how he felt about her.
Oscar quickly became close friends with Lenny and he was romantically interested in Lola, but he eventually realized that she was shallow, vain, vengeful, and selfish (much like how he was throughout most of the film). Instead, he fell in love with Angie. He also manages to make peace with Lino after admitting that he wasn't a sharkslayer, thus saving the reef from Lino and his sharks.
Oscar is a blue streaked wrasse fish with blue and yellow striped tail fins, a white belly, a yellow head, and green and blue stripes on his body.
- Oscar appears to be trained in Karate.
- Many people dislike Oscar, because they feel his egocentric personality makes him unsympathetic.
- He looks like Anthony Ramos.