Leo fights to protect his jungle from hunters who see it only as territory to claim. Tezuka built this story to break your heart over what happens when a child tries to save a world that doesn't want to be saved. The 1966 animation captures something the TV series lost: a real animal's dignity in a world that refuses to grant it.

Jungle Taitei is a 1966 feature film connected to the Jungle Emperor Leo television series from the previous year, blending adventure and drama. Its opening two minutes are lifted from that TV show, and one listing describes the rest as new material, while another says the movie is assembled from footage of several episodes. Tezuka was reportedly delighted with the result, feeling the film told his story faithfully in a way the TV version had not managed.