Well, a crossover with 'Teen Wolf' could be really exciting. The werewolves in 'Teen Wolf' have their own set of rules and hierarchies, and it would be fascinating to see how they interact with the werewolves in 'Supernatural' and how the Winchesters would handle the situation. Another interesting crossover could be with 'American Horror Story'. The different horror themes and storylines in 'American Horror Story' could blend well with the 'Supernatural' universe. Maybe the characters from 'Supernatural' have to deal with the ghosts and killers from one of the 'American Horror Story' seasons. And a crossover with 'Shadowhunters' is also a good option. The Nephilim's angelic powers and the hunters' skills could be combined to take on a greater evil that threatens both their worlds.
One idea could be a crossover with 'Doctor Who'. The Doctor and the Winchesters could team up to fight a time - traveling demon. Another could be a crossover with 'Buffy the Vampire Slayer', where Buffy and the boys from Supernatural join forces against a powerful vampire coven that has some sort of connection to the supernatural underworld in both universes. And a crossover with 'The X - Files' would also be cool, with Mulder and Scully investigating a case that turns out to be related to the monsters the Winchesters usually hunt.
One idea could be that Sam and Dean from Supernatural get thrown into the world of Good Omens. They team up with Aziraphale and Crowley to stop a demon from opening a portal that would unleash all kinds of chaos. The Winchesters' hunting skills combined with the angel - demon duo's knowledge of their own universe could make for an exciting adventure.
A cool plot could be a time - travel crossover. The 'Supernatural' crew travels to a time when Star City was in its early days. They meet a young Oliver Queen and end up changing some events that have a ripple effect on both their universes. This could lead to new alliances and new enemies. Also, a powerful witch from 'Supernatural' could put a spell on Star City that only the combined efforts of the two groups can break.
Definitely. You can find them on various fanfic platforms. A lot of these crossovers play with the idea of the Winchester brothers meeting Sherlock and Watson. They might team up to solve a case that involves both the natural and the supernatural, like a mystery where a series of murders seem to be caused by a supernatural entity but also have a logical, human - made aspect to them.
One great plot idea could be that the Winchesters from Supernatural find themselves in the world of The Walking Dead. They could use their hunting skills to fight off the walkers in a unique way. Maybe they think the walkers are some kind of supernatural creation at first and try to find a way to cure them like they do with monsters in their own world.
One idea could be that a supernatural entity from the Supernatural world somehow ends up in Central City and starts causing chaos that only the Flash's speed can help contain. For example, a demon that can possess multiple people at once and the Flash has to use his speed to track down all the possessed bodies before the demon can complete a dark ritual.
One idea could be that the Winchester brothers from Supernatural end up in the wizarding world of Harry Potter. They could be on a hunt for a supernatural creature that has found a way to hide among the wizards. Another idea is for Harry Potter and his friends to encounter a case of demonic possession in Hogwarts, and they have to team up with the Supernatural crew to solve it.
One idea could be that the Avengers have to deal with a supernatural force that is causing chaos in the city. Maybe it's a powerful demon that they can't defeat with their usual weapons and tactics. They then seek help from the Supernatural world, like Sam and Dean Winchester, who teach them about exorcisms and using holy water.
A cross - over could involve a curse in the 'Arrow' world that has a supernatural origin. Oliver Queen and his team seek the help of Sam and Dean Winchester who are experts in dealing with the supernatural. Along the way, there are clashes in their methods of operation but they gradually learn to trust each other and combine their skills to break the curse.
One idea could be that the NCIS team is investigating a series of strange murders that seem to have a supernatural element. They end up calling in the Winchesters from Supernatural for help. The two groups initially clash due to their different methods but eventually learn from each other and solve the case together.