One idea could be a crossover with the X - Men. Spider - Man could team up with Wolverine. Their different fighting styles would make for some amazing action scenes. Wolverine's brute strength and healing factor combined with Spider - Man's agility and web - slinging abilities would be a great combination.
Another option is a crossover with Daredevil. Since they both operate in New York City, they could cross paths while fighting crime. Their different senses - Spider - Man's spider - sense and Daredevil's enhanced hearing and other senses - could lead to some interesting interactions as they work together to take down the bad guys.
A crossover with Captain America could be great too. Spider - Man, with his youth and modern - day sensibilities, could learn a lot from Cap's old - fashioned values. They could fight side by side against Hydra agents or other villains, and Spider - Man could show Cap some new tricks when it comes to acrobatics in combat.
There could be a situation where a Transformer's technology gets mixed with Oscorp's experiments. This creates a new kind of threat that Spider - Man has to face. The Transformers get involved because it's their technology that's been misused. Together, they figure out a way to reverse the effects and defeat the new hybrid - like villains.
One idea could be that during a mission crossover, Spider - Man gets injured while trying to protect a civilian from an unexpected attack by a powerful enemy. Maybe he takes a hit meant for an Avenger and his suit's technology malfunctions, leaving him vulnerable.
In a Harry Potter and Spider - Man crossover fanfiction, perhaps the Venom symbiote attaches itself to a Hogwarts student. Spider - Man then has to travel to the wizarding world to stop the now - corrupted student from causing chaos. Along the way, he discovers that the magic in the wizarding world can both help and hinder his attempts to subdue the symbiote - controlled student. Harry and his friends might initially be suspicious of Spider - Man but then realize they need his unique skills.
Well, they could be in a situation where Iron Man's reputation is on the line due to some false accusations. Spider - Man believes in his innocence and decides to help him clear his name. Together, they start investigating who is behind the smear campaign. Along the way, they encounter a powerful enemy who is trying to keep them from finding the truth. This would involve a lot of detective work from Spider - Man and high - tech solutions from Iron Man.
One idea could be exploring a different origin story for Spider - Man in the fanfiction. Maybe he gets his powers from a scientific experiment gone wrong in a completely new way. For example, instead of being bitten by a radioactive spider, he could be exposed to a mutagenic serum that gives him spider - like abilities along with some unique side - effects that he has to deal with.
One idea could be a crossover with the X - Men. Spider - Man could find himself in the middle of a battle between the X - Men and some common enemy, like the Sinister Six. He'd have to figure out how to work with mutants, which is a whole new experience for him. Another idea is a crossover with the Fantastic Four. Maybe Spider - Man gets caught up in one of their space - related adventures. Reed Richards could be fascinated by his web - shooters and try to study them, while Spider - Man would be in awe of their super - scientific gadgets.
Another interesting plot could be that a mad scientist creates a device that can separate Venom from his host. However, the separation goes wrong and the symbiote energy starts to spread across the city, infecting people. Spider - Man and Venom must work together to find a way to contain the energy and save the city.
A crossover with the Avengers is also great. Picture Spider - Man having to prove himself to the more established heroes like Iron Man and Captain America. He could bring his unique street - level hero skills to a big - scale Avengers mission.
Well, a cool Venom and Spider - Man crossover fanfiction idea might be that there's a strange alien invasion. But this time, the symbiotes are being controlled by an even greater evil. Venom, having his own sense of justice, decides to work with Spider - Man. They start off not trusting each other much, but as they face the challenges, they learn to rely on one another. Also, perhaps Spider - Man has to deal with some of Venom's more violent tendencies during the fight.