One common theme could be friendship. Since they are two distinct characters, their relationship might be explored in terms of how they become friends or what they learn from each other.
Baby Dipper fanfiction may also feature some original characters created by the fanfiction writers. These could be new friends that Baby Dipper makes during his adventures. They might have unique abilities or personalities that add to the story. For example, a magical fairy friend who helps Baby Dipper on his quests.
One interesting story could be about Baby Dipper's adventures in a magical forest. He might meet talking animals and learn important lessons about friendship.
The relationship would be filled with new emotions. There would be moments of stress, like when the baby is sick and they don't know what to do. But there would also be moments of great joy, like when the baby takes its first steps. Through all these experiences, they would understand each other better and their relationship would evolve into a more complex and loving one.
One possibility could be that they find a magical baby in Gravity Falls. Dipper would be very cautious and want to research about its origin while Mabel would be all excited and want to play with the baby right away. They might take on the roles of surrogate parents, facing challenges like protecting the baby from the strange creatures in the forest.
One possible plot could be that Dipper and Wendy accidentally have a baby. They might initially be in shock but then gradually accept their new situation. They could face challenges like how to balance their own lives, which are full of mystery - solving in Gravity Falls, with raising a child. Maybe they'd have to keep the baby safe from the strange creatures in the town.
Pacifica might become more empathetic. Before having a baby, she was a bit spoiled. But now, she has to think about someone other than herself. Dipper, on the other hand, could become more responsible and protective. He was always the curious one, but now he has a family to look after.
In the fanfiction, the baby could have some special abilities or be a part of some sort of mystery. Since Dipper has had experiences with the supernatural in Gravity Falls, it's possible that the baby inherits something unique. This could lead Dipper and Pacifica on a new adventure to protect their baby from those who might want to use the baby's special powers for their own gain.
You can focus on their relationship. For example, write about a time when Baby Dipper is sick and Mabel takes care of him. She makes him soup, reads him stories, and stays by his side until he gets better. This simple act of kindness can create a very heartwarming story.
One idea could be a story where Baby Dipper discovers a magical creature in the forest and Mabel helps him keep it a secret from the adults. They go on adventures to find food for the creature and learn about its magical abilities.