Rafiki Oh boy, a tricky one lol. In relation to the lion years he's for sure at least 100 by the franchise's end, but mentally in his 70s/80s. 62 during Circle of Life and 82 at the end of the movie feels right.

Is Rafiki a baboon or a mandrill?

The male mandrill is the largest living monkey. Mandrills are also known as forest baboons. The character Rafiki in Disney's "The Lion King" is referred to as a baboon. But take a closer look, and you'll see he has the colorful face of a mandrill.

How old is Mufasa?

Anyway, since The Lion King seems to begin shortly after this, I'd wager Mufasa and Scar are both just around 5 years old at the start of the film, and Mufasa dies probably around what would have been his 6th birthday as Simba seems to be about 8 or so months at Mufasa's death.