Well, in 'the mummy fanfiction' there could be a concept where the mummy is part of a hidden society of ancient beings. This society has rules and a hierarchy that the mummy has to abide by. It could also introduce the idea of a time - traveling aspect, where the mummy gets sent to different eras and has to adapt. Or perhaps there's a concept where the mummy's appearance changes depending on the emotions it feels. For example, when it's angry, it becomes more monstrous, and when it's calm, it looks more human - like.
One interesting concept could be a crossover of magic from 'Harry Potter' and the ancient curses in 'The Mummy'. For example, perhaps the spells from Hogwarts could be used to combat the undead forces from 'The Mummy'.
One idea could be a crossover with 'Indiana Jones'. The mummy could be part of an ancient mystery that Indy is trying to solve. Maybe the mummy has some sort of power or knowledge that Indy wants.
In The Mummy 2017 fanfiction, I think the character with the most potential is the mummy. Her character has so much mystery surrounding it. You can write about her from different perspectives, like as a vengeful spirit or as a victim of a cruel fate. Then there's the female lead. She can be developed more in fanfiction, perhaps having a more in - depth relationship with the mummy, either as an enemy or as someone who tries to understand her. And don't forget the villainous characters. They can be made more complex, with their own motives and backstories that tie into the overall story of the mummy.
There might be a fanfiction where a mummy is awakened in the Twilight universe and forms an alliance with the Cullens. It could bring a whole new dynamic to the story as the mummy shares its ancient knowledge with the vampire family.
One idea could be exploring the backstory of the mummy in more detail. Maybe she had a family or a great love before she was mummified. Another could be a different take on the relationship between the mummy and the main characters, like if they formed an unexpected alliance. And perhaps a fanfiction where the mummy's powers are used for good instead of evil in the modern world.
One interesting storyline could be Imhotep and Evelyn teaming up to fight a new, more powerful ancient evil. Maybe they discover a prophecy that only their combined knowledge of the old and new worlds can stop it.
One possible plot could be that Naruto is on a mission in a desert area and accidentally stumbles upon the tomb of the mummy. When the mummy awakens, Naruto initially tries to fight it, but then realizes that the mummy has some sort of connection to an ancient chakra source. They then form an uneasy alliance to explore and protect this power from falling into the wrong hands.
One interesting 'Harry Potter Mummy Fanfiction' could be about a mummy that has magical powers and teams up with Harry Potter to fight dark forces. Maybe it uses its ancient Egyptian magic in the wizarding world.
One idea could be that the mummy monster girl is an ancient protector of a hidden tomb. A young archaeologist stumbles upon the tomb and accidentally awakens her. She initially sees him as a threat but then realizes he has a pure heart. They form an unlikely alliance to protect the tomb from those who would loot it for evil purposes.
One idea could be a crossover with the 'Indiana Jones' series. The Mummy's curse could somehow be related to an ancient artifact that Indiana Jones is after. Maybe they have to team up to stop the mummy from unleashing a greater evil.