Well, perhaps in the fanfiction, the magic of the Frozen world somehow gets intertwined with the magic of the jungle in Tarzan's world. For example, Elsa's ice magic could start to affect the climate of the jungle in unexpected ways. Tarzan, being so in tune with the jungle, tries to figure out what's going on. And Anna could get lost in the jungle and Tarzan helps her find her way back while also learning about her world of Arendelle.
One idea could be that Tarzan, while exploring the jungle, stumbles upon a strange icy portal which transports him to the world of Frozen. He meets Elsa and is amazed by her ice powers. Tarzan, with his jungle skills, could help Elsa understand the natural world in a different way. Maybe he shows her how animals communicate and live in harmony in the jungle, which in turn gives Elsa new ideas about how to interact with the spirits in her own world.
Some interesting Frozen 2 fanfiction plot ideas could revolve around the idea of a magical item. For example, there could be a magical crystal hidden deep in the forest that has the power to either save or destroy both the forest and Arendelle. Elsa and her friends embark on a quest to find this crystal before it falls into the wrong hands. Another idea is that a dark force from outside the known world tries to invade the forest and Arendelle, and the characters have to unite not only the people of Arendelle and the forest but also other magical beings to fight against it. Also, a plot could be centered around a prophecy that was never fully revealed in the movie, and Elsa and Anna must figure out what it means for their future.
One idea could be an OC who is a scientist from a modern era getting stranded in Tarzan's jungle. They could introduce new technologies or ideas to the jungle inhabitants while also learning from them. For example, they might try to set up a small communication system using basic materials found in the jungle.
The characters' interactions would be really interesting. Elsa, with her calm and powerful demeanor, would likely be cautious around Tarzan and his world. However, as she sees how he is in harmony with nature, she might start to respect him more. Anna, on the other hand, would be very enthusiastic and would try to communicate with the animals right away. Tarzan would be both intrigued and perhaps a bit confused by their foreign ways. He might teach them about jungle survival, while they could teach him about their kingdom and family bonds.
A really interesting plot could be that the gods, for some reason, send Percy on a mission to the jungle realm where Tarzan is. There, they have to work together to stop a dark force that is trying to merge the jungle world with the underworld. Tarzan uses his jungle skills and Percy his demigod abilities to battle this evil. This would involve a lot of action, adventure, and exploration of both their worlds.
Perhaps Jane discovers she's pregnant while Tarzan is away on a long hunt. She then has to fend for herself for a while, relying on the skills Tarzan has taught her. When Tarzan returns, he's overjoyed but also realizes he needs to be more present. They could face challenges like finding proper food for Jane during her pregnancy in the jungle setting.
The plot could start with Tarzan being magically transported to Arendelle. He is confused by the cold and the new landscape. Elsa, who has a deep connection with nature through her ice powers, senses his presence. They meet, and at first, there is mistrust. But as they interact, they realize they have much in common. For example, they both have a unique bond with their respective elements. Then, an evil force, perhaps a dark wizard who wants to control both the jungle and Arendelle, emerges. Tarzan and Elsa, along with Anna, Kristoff, and Sven, must work together to defeat this threat. In the end, Tarzan might find a way back to his jungle, but with a new understanding and friendship with the Frozen characters.
A great plot for Frozen fanfiction could be a time - travel story. For example, Elsa is sent back in time to when her parents were young. She has to figure out how to get back to her own time while also trying not to change the past too much. But she might also learn some secrets about her family's past and her own powers. Another could be a story about a competition in Arendelle. Anna decides to hold a magical - themed competition, and people from all over come to show off their skills. Elsa has to judge, and in the process, she meets someone who seems to have powers similar to hers but uses them for evil. Anna, Elsa and Kristoff then have to stop this person.
A plot idea might be that there is a strange blizzard that is not caused by Elsa. Kristoff, suspecting foul play, comes to Elsa for help. Together, they discover a dark sorcerer is behind it. As they battle the sorcerer, Kristoff helps Elsa see that she doesn't have to be afraid of her powers and can use them more freely. This could lead to a deeper friendship or more between them.
Well, a cool plot might be that Elsa's ice powers are actually a form of ancient magic that was lost in the wizarding world long ago. Harry and his friends figure this out and bring Elsa to Hogwarts to study her powers. Meanwhile, Anna follows and gets into all sorts of adventures at Hogwarts, like trying to fit in with the students from different houses. Also, the dementors could be attracted to Elsa's coldness, but instead of sucking out her soul, they end up getting frozen by her powers.