Bewitched (1964)

Season 5: Episode 11

Tabitha goes to pre-school for the first time and meets Amy, a classmate. When the teacher groups the children in animal groups, Amy gets chosen to be a toad in the toad group, but she wants to be in a butterfly group. Tabitha misunderstands her request and actually turns her into a butterfly! Samantha, who has been watching the whole thing through the window, chases Amy the butterfly all around the city and catches her so Tabitha can change her back.