Mammy in the Forest
Bubu and Totto force an old horned owl to make a poisonous drug, and give it to Leo. The two are pleased because they think they have killed Leo by poison. However, the drug causes only numbness. When they find that Leo is still alive, they try to make the old owl create a real poison this time. Source: tezukaosamu.net
EP 24 - Mammy in the Forest

1965
Kimba the White Lion
The series follows the adventures Leo, a young lion cub. Leo becomes king of the jungle when his father, the previous king of the jungle is killed by a human hunter.
(Source: Anime News Network)