Shark Tale(2004)

Oscar is an underachieving blue streak cleaner wrass who works his dad's job as tongue scrubber at the local Whale Wash. His arrogant boss, a pufferfish named Mr. Sykes explains that Oscar owes him 5,000 clams in payments. His friend Angie, the wash's secretary, gives him an old pearl necklace, which Oscar instead uses to bid on a horse race to impress a beautiful fish named Lola. After his horse loses the race, Oscar is fired from his job. Oscar soon comes across a shark, killed by an anchor when teaching his vegetarian brother about being a shark, and decides to take credit for killing him. It's your typical mafia gangster comedy with a fishy twist!