As Disney animators developed the story for “The Lion King,” they turned to World War II propaganda footage to determine the aesthetic of Scar’s rule. They were also inspired by 1930s footage to stylize segments of "Be Prepared" with yellow and black to mimic vintage newsreels of the Depression era.
In the late 2010s, Disney Television Animation produced a series called "The Lion Guard" which revealed how Scar turned from good to evil. It showed how he got his scar after getting attacked by a venomous snake, which earned him the mocking nickname from his own brother Mufasa.
In a deleted scene for the original animated movie, Scar was shown wanting Nala to be his queen. It eventually made its way into the Broadway musical as a song called “The Madness of King Scar,” where Scar thinks aloud about his need to produce an heir before demonstrating creepy attention towards Nala.
In “The Lion King 2: Simba’s Pride,” it is revealed that Scar may have had further plans for Pride Rock through his mysterious connection to the outlaw lion Kovu. Kovu’s mother Zira claimed that Scar had hand-picked Kovu to be his heir, and that Kovu was born shortly before the outlaw lions were exiled.
Jeremy Irons developed vocal problems while recording “Be Prepared,” so the last verse of the song was taken up by prolific voice actor Jim Cummings. If you listen closely, you may be able to tell the slightest of differences in Scar's voice toward the end of the song, but the magic trick is pulled off expertly, and it's hardly noticeable.