Way before Disney strayed from its habit of telling tales centered only on docile, lily-white princesses, a black animator helped bring its stories to life. In “Sleeping Beauty,” a crew of cheery, vibrant birds flit across the screen; in “The Sword in the Stone” a no-nonsense owl keeps Merlin company. Floyd Norman worked as a clean-up artist and an assistant animator on these films, respectively. He helped finesse their aesthetic, but his work was uncredited.