Disney have revealed that Mufasa and Scar are not brothers in 'The Lion King'

"There was always this thing about well, how do you have these two [male] lions?"

“Occasionally there are prides that do have two male lions, in an interesting dynamic because they’re not equals. One lion will always kind of be off in the shadows."

"We were trying to use those animal truths to underpin the story so we sort of figured Scar and Mufasa couldn’t really be from the same gene pool.

"In fact, that’s what [Scar] says. There’s a line, he goes, ‘I’m from the shallow end of the gene pool.’"