If you visit the Contemporary Resort, look in the Grand Canyon Concourse (where the monorail runs) for the murals created by Mary Blair. On one of the walls is a mural of a mountain with two goats at the top right. Look for one of the goats to have 5 legs!
Why would Mary Blair create a goat with 5 legs? Rumor is, she believed that no piece of artwork should be perfect because only God was perfect. In turn, she purposely created the 5-legged goat in the mural so it would not be perfect. Disney also created a pin of the 5 Legged Goat!