Marty the zebra, Alex the lion, Gloria the Hippopotamus and Melman the Giraffe live in the Central Park Zoo in New York. On Marty's tenth birthday, Marty starts to have doubts that the zoo is where he belongs, and finds that life in the zoo is boring. That night, a penguin living in the zoo named Skipper decides to break out of the zoo, and invites Marty to come with him, and gives Marty directions on how to clear paths. Skipper, in order to escape himself, is forced to abandon Marty in the process, but gives him more directions. Marty manages to make it to the main exit and leave. Realizing this, Alex, Melman and Gloria decide to go and look for him. As they find him, they are surrounded by police, tranquilized, and sent to a wild life reserve. Skipper and his team of penguins: Private, Rico and Kowalski are also on board. They escape from their crate and head for the bridge where they knock the captain unconscious and turn the ship around to Antarctica. Marty, Alex, Melman and Gloria fall into the ocean in the process. Alex is washed onto a beach unconscious, and soon wakes up. Finding an opened crate which belonging to Marty on the beach, he concludes that his friends are there too, and goes off to find them. In the jungle, he helps different animals with their tasks, and in return they give him his friends' whereabouts and finally reunites with his friends.