Mister Rogers' Neighborhood (1968)

S1E32 Red Monster Pt 2: No one has ever seen a monster

In this episode, Mister Rogers makes a grand entrance carrying a collection of masks. He demonstrates that wearing a mask doesn't alter who he truly is. Meanwhile, the inhabitants of the Neighborhood of Make-Believe are on a quest to uncover the identity of a mysterious creature rumored to be a red monster lurking nearby. As they investigate, they learn valuable lessons about perception and identity.