Crossover (fiction)

Okay kiddo, so you know how there are different stories with different characters, right? Well, sometimes the characters from different stories meet each other and have an adventure together, that's called a crossover. It's like when you have a playdate with your friend from school and you both play with your toys together. In a crossover, the characters also play together, but in a story, kind of like a big picture book or a movie. Some people really like crossovers because it's fun to see their favourite characters from different stories interact with each other.