What are some interesting ideas for a rotg and httyd crossover fanfiction?

One idea could be to have Toothless meet Jack Frost. Maybe Jack could try to ride Toothless and they could have an adventure together exploring the skies and the wintery landscapes. It would be cool to see how their different powers interact, like Toothless' fire against Jack's ice.

A cool concept would be a hybrid character. Imagine a Spartan who has been genetically altered with some dragon DNA. This character could have the strength and combat skills of a Spartan along with the ability to breathe fire or fly like a dragon. Or perhaps the Covenant could be interested in the dragons in the HTTYD world because they see them as a new form of powerful weaponry to add to their arsenal.

Another interesting concept is a villain crossover. Mother Gothel could team up with a dragon hunter from HTTYD. They could both have their own motives, like Mother Gothel wanting to use the dragons to keep Rapunzel trapped forever, and the dragon hunter just wanting to capture the dragons for profit. Hiccup and Rapunzel would then have to join forces to stop them. This would create a lot of action - filled scenes and also some interesting character interactions as they try to outwit the villains.

The characters can interact in many ways. For example, Jack Frost can use his powers to play with the httyd dragons. He could create ice sculptures for them to play with or use his ice slides to race the dragons in the sky. Hiccup could show Jack Frost how to ride a dragon, and in return, Jack could teach Hiccup some of his tricks for moving around quickly and quietly.

One idea could be that Danny's ghost powers somehow interact with the dragons in HTTYD. For example, his intangibility might make him able to pass through dragon fire without getting burned, and this could be a crucial skill when dealing with a new, more dangerous breed of dragons. Another idea is that Danny gets transported to the world of HTTYD and has to use his ghostly abilities to fit in and help the Vikings. Maybe he can use his flight ability to race against the dragons, which would be an exciting plot point.

Perhaps the vikings of Berk accidentally open a portal to Spyro's realm while exploring a new area. Spyro is intrigued by the vikings and their relationship with dragons. Meanwhile, Hiccup tries to understand Spyro's abilities and how they can be used to improve Berk's defenses. They could team up to rescue some baby dragons that were captured by an evil force from both their worlds.

One popular idea is a httyd and How to Train Your Knight crossover. Imagine the dragons in a world filled with knights and castles. Another could be a crossover with a modern - day setting, like httyd characters in a big city dealing with new challenges. And there's also the idea of a crossover with a fantasy world like Middle - earth, where the dragons interact with different magical creatures.

One idea could be that the dragons in HTTYD are attracted to the cold of Frozen's world and they fly there. The people of Arendelle are initially scared but then they learn about the dragons from the dragon riders. Another idea is that Elsa's ice powers somehow have an effect on the dragons, like making their fire breath turn into ice breath for a short time.

With Jack Frost, his character can be developed by showing his reaction to the dragons. He might be fascinated by them at first but also a bit scared. His relationship with Toothless could be a key part. Maybe Toothless doesn't trust him immediately, and Jack has to earn that trust. This would show his determination and his ability to connect with different beings.