A unique idea for a Croods time travel fanfiction could be that the Croods find a time - traveling device left by an alien race. This device takes them to different points in time and space. For example, they could end up on a planet where all the creatures are made of light. How would they interact with these strange beings? Another idea is that the time travel is caused by a magical spell cast by a prehistoric shaman. The Croods then have to deal with the consequences of traveling to a time where magic rules everything.
First, research about the Croods' world, like their lifestyle, relationships, and the prehistoric setting. Then, think of an interesting time travel concept. For example, what if a Crood accidentally travels to the future? Next, create a plot that has conflict and resolution. Maybe they struggle to adapt to the new time's strange things. Finally, keep the characters' personalities true to the original while adding some growth due to the time travel experience.
A crossover with a magical world like 'Harry Potter' could also be cool. The Croods enter the wizarding world and are introduced to magic. Eep might be fascinated by the magic wands and spells, while Grug struggles to understand the concept of magic that defies his idea of the physical world.
Another idea is that Eep and Guy start teaching the Croods family new things they've learned from each other. Eep shows the family some of Guy's inventions, like the fire - making device. Guy, on the other hand, helps Eep teach the family about being more open - minded and less afraid of new things. This creates some funny and heartwarming moments as the family adjusts to these new ideas, with Eep and Guy at the center of it all.
She could travel to an alternate timeline where the zombie apocalypse never happened. It would be interesting to see how she reacts to a normal world and how she might try to bring back some of the things she learned in her own timeline.
He could time travel to the era when dinosaurs roamed the earth and have to use his wits, similar to how he did in 'Indiana Jones' movies. Maybe he's on a mission to find a rare artifact that has time - traveling properties. This would put him in a completely different and dangerous setting.
One unique idea is exploring the dark side of the Triforce. In some fanfictions, after Ocarina of Time, the power of the Triforce is misused or has unforeseen consequences. Also, there are fanfictions that focus on the Sheikah tribe's role in the post - Ocarina of Time world. They were important in the game, and these fanfictions expand on their influence, like how they might be involved in protecting ancient secrets that could change the future of Hyrule.
One unique element can be the alteration of historical events. For example, in some fanfics, Steve and Bucky's time travel allows them to change certain things in their past, like preventing Bucky's fall. This creates a whole new timeline and new possibilities for their relationship.
One idea could be a story where Tracer accidentally travels back to the Omnic Crisis era. She could meet the younger versions of the original Overwatch founders and try to help them in ways that might change the future of Overwatch. Another could be Reinhardt going back in time to his early days as a Crusader and having to relive some of his toughest battles with the knowledge he has now.
One interesting idea could be Tsuna going back in time to prevent certain tragedies in his family's past. This would change the whole dynamic of the Vongola family in the present.
One interesting idea could be Itachi traveling back in time to prevent the Uchiha massacre. He could use his knowledge of future events to find a way to resolve the conflict between the Uchiha clan and the village without bloodshed. Another idea might be Itachi traveling forward in time to see the consequences of his actions and how his younger brother Sasuke has turned out. He could then try to guide Sasuke in a different direction from the future he witnessed.