Doraemon Movie 03: Nobita no Daimakyou

Nobita adopts a mysterious stray dog named Peko, who soon leads Doraemon and the others toward an unexplored region deep in Africa. Beyond the dangerous jungle they discover a hidden civilization of intelligent dogs and learn that Peko is actually its missing prince.

During his absence, the kingdom has fallen under the control of the tyrant Daburanda, who intends to use an ancient weapon to secure his rule. Nobita and his friends join Peko's fight to reclaim his homeland, crossing hostile wilderness and ancient ruins on a journey that demands far more courage than their original sightseeing adventure.