A possible plot could involve a human inventor who accidentally creates a portal to the Spyro world. Once there, they use their knowledge of mechanics and technology to help the Spyro characters. For example, they could build new gadgets to help Spyro in his quests or create defenses for the dragon villages against the attacks of the enemies. The human's presence could also introduce new concepts of problem - solving to the Spyro world.
Another interesting concept is a human with a special ability, like being able to communicate with animals in our world, ends up in the Spyro world. In this world, their ability is enhanced and they can communicate not only with the normal animals but also with the magical creatures. They could use this to bridge the gap between different species in the Spyro world and bring about peace in a region that has been torn by conflict.
One idea could be a human from our world getting transported into the Spyro universe. They could start off as a confused outsider but then gradually learn the ways of the Spyro world, befriending the dragons and other creatures. They might even discover a hidden power within themselves that helps in a great battle against the forces of evil in the Spyro realm.
One idea could be a crossover with another fantasy world like 'The Elder Scrolls'. Spyro could find himself in Skyrim, facing dragons of a different kind. Another could be a crossover with 'Harry Potter', where Spyro enters the wizarding world and has to deal with magic there. Maybe he helps Hogwarts students in a dragon - related task.
Another plot could involve Spyro and Link from The Legend of Zelda. Spyro could end up in Hyrule. Link, being the hero, initially is cautious of Spyro. But when they realize they both have a common enemy - Ganon who wants to use Spyro's powers for his own dark purposes, they join forces. Spyro can help Link reach places he couldn't before with his flying, and Link can use his swordsmanship and knowledge of Hyrule to guide Spyro.
A third idea is a human from a medieval - like world where dragons are feared. This human, who has always been curious about dragons, sets out on a journey and stumbles into Spyro's world. At first, the dragons are suspicious of the human, but Spyro vouches for them. Together, they work to bridge the gap between the two species' understanding.
A crossover with 'Alice in Wonderland' could also be cool. Spyro finds himself in Wonderland and has to navigate through the strange and magical places. He could team up with Alice to defeat the Queen of Hearts who has somehow gotten her hands on a powerful magic item from Spyro's world and is using it to cause chaos in Wonderland.
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.
Well, a great plot for a Spyro and Fairy Tail crossover fanfic could involve Spyro's dragon powers being mistaken for a new type of lost magic in the Fairy Tail world. The Fairy Tail guild members might be intrigued and try to recruit Spyro. Meanwhile, Spyro is just trying to find his way back to his own realm. He could end up sharing some of his dragon skills with the mages, like his fire - breathing ability, which could be enhanced by Fairy Tail's magic, creating a whole new kind of power.
One idea could be that the two Spyros, from different dimensions perhaps, have to team up to defeat a new powerful villain that neither could face alone. For example, a dark sorcerer who is draining the magic from all the dragon realms. Another could be that they initially mistake each other for an enemy and engage in a friendly sparring match before realizing they are on the same side. Then they combine their unique skills, like one Spyro's amazing flying maneuvers and the other's powerful fire breath, to solve a mystery in the dragon world, like the disappearance of an ancient dragon artifact.
One idea could be a human detective who gets transported to Zootopia and has to team up with Judy Hopps and Nick Wilde to solve a case that involves both the human and animal worlds. Maybe there's a mystery item that has strange effects on both species.
One idea could be a crossover where Sans from the game enters a human world during a major historical event like the Industrial Revolution. He could interact with inventors and workers, his magic and unique personality causing all sorts of comical and thought - provoking situations.
One idea could be that Sonic gets transported to the human world and has to adapt to a normal high school life while still trying to keep his super - speed a secret. He could make friends with some humans who gradually discover his true identity and help him fight against an evil force that has also made its way into the human world.