Kimba the White Lion
When Mufasa (the lion) appears in the clouds before Lisa, he says "You must avenge my death, Kimba... I mean, Simba." This is a reference to the idea that Disney's was not original. The Lion King's idea is very similar to a Japanese anime show called Kimba the White Lion, which originated in the 60s, where the main character is a white lion named Kimba who's father also dies.