First Live Comic Crossover
The Batman series was possibly the first-ever superhero series that had a live-action comic book crossover. Long before the Marvel Cinematic Universe, Green Hornet and Kato appeared in an episode of the 1960s Batman series to help Batman and Robin.
Catwoman’s Henchwoman
Lesley Gore was a singer who became famous for her song “It’s My Party.” but she wasn’t just a singer, she was also an actress who featured in two episodes of Batman as one of Catwoman’s henchwomen and as Robin’s love interest.