Sora no Momotarou

Made by the same people. Both have the same characters and general premise of fighting an big animal terrorizing small animals using war vehicles. Umi no Momotarou is much shorter and doesn't spend as much time on the setup as it assumes you have seen Sora no Momotarou. 

Both are short, very old, black and white movies from 1930-40. Both show a story about a hero Momotaro that fights eagles on a sea while riding airplane with his animal companions. Both have anthromorphic animals. Both can be taken as anti-america propaganda, but it´s more obvious in Momotarou no Umiwashi.