In the Forest of Okoya, Koko is a feral child who has been raised as a Pokémon by the Mythical Pokémon Zarude. Koko has grown up never doubting that he is a Pokémon even though he can't really use any sort of moves. Ash Ketchum and Pikachu meet Koko and help him protect the Great Tree from the crooked scientist Dr. Zed.

Determined to prove its superiority, a bio-engineered Pokémon called Mewtwo lures Ash, Pikachu and others into a Pokemon match like none before.

The Team Rocket leader, Giovanni, has found Mewtwo in a remote area of the Johto region. As Giovanni tries to re-capture Mewtwo, Ash and his friends are kidnapped by Domino, a new Team Rocket member, while trying to rescue Pikachu from Jessie and James. The Clone Pokemon are also captured and are then used as bait for Mewtwo. The situation then becomes a battle between the wills of Mewtwo and Giovanni; and Mewtwo also tries to discover if it and the clones have a purpose in life, even though they are products of science.

When Nami falls ill, the Straw Hats seek medical care for her on Drum Island. There they meet reindeer doctor Tony Tony Chopper and the Wapol Pirates.

A collection of Warner Brothers short cartoon features, "starring" the likes of Daffy Duck, Porky Pig and Wile.E.Coyote. These animations are interspersed by Bugs Bunny reminiscing on past events and providing links between the individual animations which are otherwise unconnected. This 1979 feature-length compilation includes several of his best cartoons. Among the 11 shorts shown in their entirety are the classics "Robin Hood Daffy," "What's Opera, Doc?," "Bully for Bugs," and "Duck Amuck". The Bugs Bunny Road Runner Movie provides a showcase not only for Jones's razor-sharp timing, but for the work of his exceptional crew, which included designer Maurice Noble, writer Mike Maltese, composers Carl Stalling and Milt Franklyn, and voice actor Mel Blanc.