I'm not really sure. It could be a new character or even an existing one from either ROTG or the Elsa-related universe. We might have to keep reading to find out!
There's a 'rotg crossover fanfic' that pairs RotG with the Avengers. It's exciting as it pits the magical and dream - based powers of RotG against the superpowers of the Avengers. The story often has intense battle scenes and unexpected alliances.
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.
First, you need to know the universes you want to cross over well. For RotG, understand the characters, their powers, and the rules of their world. Then, think of a unique concept for the crossover. It could be a shared threat or a common goal that brings the two universes together.
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.
It could be someone from the other universe in the crossover. For example, if it's a crossover with a superhero universe, it could be a character like Superman. The combination of Naruto's strong ninja genes and Superman's superpowers would make for an extremely powerful child. Or it could be a character from a high - fantasy world, like a powerful mage. Their union would bring about a child with a mix of magic and ninja abilities.
A common theme is the exploration of new powers. When Elsa crosses over into another universe, her ice powers often interact in new and unexpected ways with the elements or magic of that world.
It could vary depending on the specific fanfiction. Maybe it's a character introduced especially for that story.
In this fanfiction, Marshmallow could be a significant character. He's a large and somewhat intimidating snow creature created by Elsa. But with the baby on the way, he could become a gentle protector. He could stand guard outside their home to keep any potential threats away. Also, the trolls from the Frozen universe could play a role. They are wise and could offer their knowledge on how to take care of a baby with magical powers. They might even perform a special ceremony for the unborn baby.
Perhaps it could be Kristoff. Although he was more interested in Anna in the original story, in fanfiction, the relationships can be reimagined. They could have developed a closer bond over time and he could be the father.
She could interact with Daenerys Targaryen. They are both strong female characters with special powers. They might initially be rivals, both vying for power and influence in Westeros, but then realize they can achieve more by working together. For instance, Elsa could use her ice powers to cool down the hot deserts that Daenerys has to cross with her armies.