I have written a couple crossovers between different works. They’re in screenplay format, and most aren’t particularly long. Like my fanfiction, I wrote these just for fun.
I’d recommend only reading the crossovers if you’ve watched/read both works they’re about.
Star Trek: Voyager and Adventure Time: A machine created by Princess Bubblegum accidentally makes a wormhole to the Delta Quadrant, sending characters from both sides into the wrong universe.
Star Trek: Deep Space Nine and Doctor Who: The Doctor and Rose land on Deep Space Nine, where the Borg and the Daleks have formed an alliance and are attacking the station.
Star Trek: The Original Series and “The Tempest” (Shakespeare play) : Prospero accidentally beams the crew of the Enterprise down to his planet (this is a sci-fi AU). The Enterprise crew interact with the Tempest characters, and figure out some very important facts about the island. (This one is pretty long)
I also wrote a crossover between Star Trek (the original), Star Wars, and The Hitchhiker’s Guide to the Galaxy with a friend a while ago.
I don’t own the rights to any of the TV shows I cross over.