Shark Tale
Oscar, a bottom-feeding fish, sees his opportunity when a shark who is the son of the shark Mafia leader is killed by a dropped anchor. Oscar takes credit by convincing everyone that he's responsible for removing this bad guy from the underwater society, but he soon finds that being known as someone who killed a member of the Mob has its drawbacks.
The Casts are Will Smith, Robert De Niro, Renée Zellweger, Angelina Jolie, Martin Scorsese, Michael Imperioli, Jack Black, and Katie Couric.