There could be. A lot of fan - fic writers like to create crossovers between different universes. Elsa from 'Frozen', the Creeper from Minecraft and Spiderman are all very popular characters, so it's possible that someone has written a story involving them. However, it might not be very common given how different their worlds are.
In a 'anna elsa x mother fanfic', the mother could be a central figure in resolving the conflicts between Anna and Elsa. Maybe she was lost long ago, but through some magical means, she comes back in a form to guide them. This could add a new layer of emotional depth to their story, as they deal with both the joy of having their mother back and the challenges of following her advice in a world that has changed since she was last there.
For Percy, his loyalty and sense of adventure can be emphasized. He could be the one to initiate contact with Elsa, seeing her as a new and exciting mystery. His skills in combat and his ability to think on his feet would come in handy when they face challenges together. For Elsa, her growth from a withdrawn and fearful queen to someone more open and trusting can be shown. Meeting Percy, who is so different from the people in her world, could be a catalyst for this change.
Harry Potter himself would be likely to interact with Elsa. Given his own experiences with unique powers and his role as a hero, he would be sympathetic to Elsa's situation. They could bond over their shared sense of responsibility and their ability to do things that others can't. Harry could also introduce Elsa to his friends and the world of Hogwarts.
One common theme is the idea of redemption. Pitch is often seen as a villain, and in these fics, his relationship with Elsa can lead to him finding a new path. For example, Elsa's purity might inspire him to change.
Love and friendship are often themes in 'reader x elsa fanfic'. The relationship between the reader and Elsa can range from a deep friendship to a romantic love. In some fics, they start as friends and gradually fall in love as they go through adventures together. Also, the theme of self - discovery for both the reader and Elsa is quite common. They learn more about themselves through their interactions.
I'm not sure if there is an existing 'jack frost x elsa pregnant fanfic' specifically. There are a vast number of fanfics out there in the fandom world, and it might exist, but it's not something that I can confirm with certainty. You could try searching on some major fanfic websites to see if you can find one.
One common theme is the power struggle. Since both Elsa and Pitch have strong and distinct powers, many fanfictions explore how they deal with each other's powers. For example, Elsa's ice powers might be a counter to Pitch's nightmares or vice versa.
Yes, there are some. You can start by looking on fanfiction websites like Archive of Our Own. Just search for 'elsa x olaf fanfic' and you'll find various stories written by fans.
One common theme is self - discovery. The OC often helps Elsa to further understand herself and her powers. Another theme is friendship. They start as strangers and develop a deep bond. For example, in many stories, the OC might be the first person to truly accept Elsa for who she is.