Perhaps in the fanfiction, Dagur is exiled from his tribe and Female Hiccup finds him in a weakened state. She decides to help him get back on his feet. As she teaches him new ways of living and interacting with dragons, they grow closer. Dagur starts to change his old ways because of her influence, and they fall in love while exploring new lands and taming new dragons together.
One plot idea could be that Dagur and Female Hiccup are forced to team up to face a new threat in their land. They start off not trusting each other but as they go through various challenges together, they begin to respect and then develop feelings for one another. Another could be a story where Female Hiccup has to save Dagur from a dangerous situation and in the process, Dagur realizes how strong and amazing she is, leading to a friendship that could turn into something more.
The unique character dynamics. A female Hiccup would bring a different perspective to the relationship with Dagur. Their interactions can be full of surprises and new interpretations of the original story's relationships.
Another plot idea is that a strange illness starts affecting the dragons in Berk. Toothless is one of the first to show symptoms. Hiccup, being the dragon expert, sets out to find a cure. He and Toothless travel far and wide, facing many challenges along the way. They meet other dragon riders from different lands who may or may not be helpful in their quest for the cure. This journey tests their bond and shows how much they rely on each other.
The contrast between their personalities. Hiccup is more calm and calculating while Dagur is wild and impulsive. When a fanfic plays on this difference, it can create really engaging storylines.
A really interesting plot could be a time - travel one. Maybe Female Hiccup travels to Jack Frost's past or vice versa, and they have to adjust to the different time periods while also falling in love. Or perhaps there's a plot where they are both tasked with protecting a special, magical artifact that has the power to change the balance of their worlds, and they have to overcome their differences to succeed.
One plot idea could be that Hiccup, as a female, has unique ways of bonding with the dragons. For example, she might use her more empathetic nature to understand their needs better than in the original story. Another could be that she faces different challenges in the Viking society which is often male - dominated. Maybe she has to prove herself even more to be accepted as a dragon rider.
You can start by looking on fanfiction platforms like Archive of Our Own (AO3). It has a vast collection of fanfics on various topics, including those about Female Hiccup and Dagur. Just use the search function and type in relevant keywords.
Well, a plot could involve Hiccup and Toothless getting separated. Hiccup then has to go on a journey to find Toothless, facing many challenges along the way, like bad weather and other dangerous creatures. Or perhaps they find a magical object that gives Toothless some new, unexpected powers. Hiccup then has to help Toothless learn to control these powers. Also, they could be transported to a different time period, and have to find their way back while also dealing with the differences in that era.
The relationship can be developed through shared adventures. For example, they could go on a quest to find a rare dragon. Along the way, they face difficulties like harsh weather and dangerous terrains. By relying on each other's skills, they start to bond. Dagur's strength and combat skills combined with Female Hiccup's intelligence and dragon - handling abilities make them a great team. This mutual dependence can lead to deeper feelings.
Perhaps there could be a plot where the pregnancy is a sign of a new era for the tribe. Hiccup might see it as a chance to bring new ideas about family and community to the Vikings. He could start initiatives like building better homes for families or creating safer areas for children to grow up in, all inspired by the upcoming addition to his own family.
One interesting plot idea could be Hiccup and Astrid going on a secret adventure to a new, uncharted island. They face new dragons and have to work together to survive. Another could be a story where they have to deal with a rift in their relationship due to a misunderstanding, like Astrid thinking Hiccup is spending too much time with a new dragon rider. A third idea is a time - travel plot where they go back in time and have to change something in Berk's history to save the future.