Good, old Rafiki: you can always count on him to have a giant gourd full of beans, a head full of prophecies, and a disarmingly red butt. His name actually means "friend" in Swahili, which speaks volumes of his character.
Although he can be kind of goofy, Rafiki is basically the spiritual center of The Lion King: he alone is connected to both the earthly world and the spirit world, the past and the future, the heavens and a magical river that can reveal the ghost of your dad if you look into it long enough.
Rafiki plays a crucial role in the film. Without his hocus-pocus, Simba would not have been able to "reunite" with his ghostly father and realize that he's wasting his time lounging around the jungle with Timon and Pumbaa.
When Simba first runs into Rafiki, he's a little peeved about everything, especially since Rafiki keeps hitting him in the head with a giant stick in order to teach him a lesson about how we must learn from our pasts. But then, Rafiki enables Simba to see and speak with the ghost of his father, which gives Simba the strength he needs to return to Pride Rock and fight the good fight.
Rafiki also delivers the most important lesson Simba will ever receive about his past:
"Oh, yes, the past can hurt. But, the way I see it, you can either run from it … or learn from it."
Both a soothsayer and a noble fool—i.e., someone who acts silly but really knows a lot—Rafiki is a true source of goodness and wisdom in The Lion King.