In New York City, a charismatic magician named Hector P. Valenti wants to try out on a national talent show but is constantly rejected. One day after a failed audition, he wanders into an exotic pet store, where he finds a singing baby crocodile and names him Lyle. Seeing Lyle as an opportunity to become rich in the talent business, he places his three-story Victorian brownstone house as collateral for their performance, but Lyle experiences stage fright during the premiere and Hector loses the house. Hector is forced to move out and reluctantly leaves Lyle to fend for himself while he tries to make more money. Eighteen months later, Mr. and Mrs. Primm and their young son Josh move into the house. Josh is initially terrified of moving into his new home and struggles to make friends at school. One night, he discovers Lyle, now fully grown, living in the attic, and they become friends when Lyle saves Josh from a mugger and demonstrates his singing talent. Josh's stepmother and father eventually find out about Lyle, and though initially terrified of him, bond with Lyle over their favorite hobbies. One day, Hector returns to the house to visit Lyle, as an agreement states he can live in the house fifteen days a year. He makes another attempt to get Lyle to perform on stage, but it fails as Lyle still has stage fright, apart from when performing for the Primms. Meanwhile, Alistair Grumps, the Primms' unfriendly downstairs neighbor, becomes annoyed by the loud activity caused by Lyle, Hector, and the Primms. Determined to put an end to it, he has cameras installed to discover what is happening but manages to achieve his goal by bribing Hector to sell out Lyle in exchange for money to pay his debts. Lyle cannot convince the authorities of his benevolent nature because of his stage fright and is locked up at the zoo. Feeling guilty for what he did to Lyle, Hector goes to break him out of the zoo with Josh's help, who was initially unwilling to help after learning Hector sold Lyle out. On Josh's insistence, Hector and Lyle reconcile with each other before Lyle escapes with Josh to the talent show, while Hector distracts the authorities. On stage, Lyle manages to overcome his stage fright with help from Josh, receiving acclaim from the audience and viewers for his singing talent. One month later, a trial is held to determine whether or not Lyle may be free. The judge ultimately decides to rule over Grumps in favor of Lyle when Hector reveals that the deed to his house was written out to his grandmother, that was hidden away under Grumps' bed, who built the house and founded the New York City Zoo where Lyle was previously kept, allowing her to keep exotic animals as pets. After the trial, the Primms celebrate Lyle's freedom, and Grumps' implied eviction, by taking him on vacation, while Hector becomes acquainted with a new talented animal: a beatboxing rattlesnake named Malfoy, owned by Josh's friend, Trudy.