If I'm Dyin' I'm Lyin' - S2-E9
Revealing mistake: When one of the Gumbels is holding a pencil in his mouth and nodding repeatedly, the shaft of the pencil moves with his mouth, but the tip of the pencil (protruding from his hand) stays still. (00:17:35)
Answer: Mort is Jewish, and Walt Disney was said to be antisemitic. So it would make sense in a Disney universe all the inhabitants would share his supposed beliefs.
MasterOfAll