Pee-wee's Playhouse (1986)

Monster in the Playhouse - S1-E9

Revealing mistake: As the monster hops from behind the snack island, the actor's white shoes can be seen for a moment. (00:30:00)

Movie Nut

Pee-wee: You all remember what to do whenever anybody says the secret word right?
All: Scream.
Pee-wee: That's right. For the rest of the day, whenever anybody says the secret word, scream real loud. Ready? Let's try it.