A possible plot is that Killer Croc starts to have dreams that seem to be memories from a past life, and he embarks on a journey to find out the truth about his origin. In another scenario, he could be the target of a new villain who wants to capture him and use his strength in some sort of gladiator - like arena. This would lead to Killer Croc having to fight not only for his freedom but also for the safety of the innocent people who get caught up in the villain's scheme. Additionally, there could be a story where he falls in love with a character who sees past his exterior, and they have to overcome many obstacles together.
One plot idea could be Killer Croc forming an unlikely alliance with a small group of outcasts in the city. They initially fear him because of his appearance but come to realize he has a good heart. Another could be Killer Croc's struggle to adapt to a new environment outside of his usual sewers, perhaps in a more rural area where he has to deal with different challenges. A third idea is a story where Killer Croc discovers a hidden power within himself during a fight with a powerful enemy and has to learn to control it.
One plot idea could be that the OC is a scientist who is studying Killer Croc. They start off with a professional relationship but gradually develop a strange bond. Maybe the OC discovers a way to temporarily suppress Killer Croc's more violent tendencies, and this leads to them spending more time together. As they interact, the OC begins to see the humanity in Killer Croc that others overlook.
One plot idea could be that Killer Croc somehow ends up in the Naruto world and has to learn chakra control. Maybe he starts as a villain but then teams up with Naruto's group against a greater threat.
One idea could be that Naruto is transported to a different universe where he somehow gets cursed and starts to transform into Killer Croc. As he struggles with this new form, he has to find a way to reverse it while also dealing with the reactions of the people in this new world.
To create a believable character arc for Killer Croc, start with his backstory. Show his early life and how he became the way he is. Maybe he was once an ordinary person who was experimented on. Then, as the story progresses, have him face challenges that force him to change. For example, if he meets a group that accepts him, he might start to become more trusting. By the end, he could be on his way to becoming a more heroic figure, or at least less of a feared outcast.
Well, for Killer Croc crossover fanfiction, a cool concept could be a crossover with Swamp Thing. Since both have a connection to the more primal and swampy aspects of nature. They could either be allies against a common enemy that's polluting their habitats or be in a conflict over territory. Also, a crossover with the Suicide Squad could be interesting, showing Killer Croc's interactions with other anti - heroes and villains in a different mission scenario.
One idea could be that Jeff and Jane are forced to team up against a common enemy in a spooky forest setting. As they fight side by side, they start to see each other in a different light. Another could be a time - travel plot where they end up in a different era and have to adapt together. And perhaps a plot where they both get trapped in a haunted mansion and have to find a way out while dealing with their complex relationship.
One plot idea could be that Slenderman and Jeff the Killer are forced to team up against a common enemy, like a powerful demon. As they work together, they start to understand each other's motives and develop an odd friendship that has hints of a deeper relationship. Another idea is that they find themselves in a strange dimension where they have to rely on each other to survive, and during this time, their relationship blossoms in unexpected ways. A third plot could be that they are both haunted by their pasts and find solace in each other's presence, leading to a relationship that defies the norms of their murderous existences.
In Batman Killer Croc fanfiction, there could be an unusual alliance where Killer Croc teams up with Batman against a common enemy. This enemy could be a new supervillain who has a plan to take over Gotham's underworld and Croc's territory. Croc might see the benefit of working with Batman temporarily to protect his own interests.
There are fanfictions that explore their relationship in different ways. Maybe in one, Baby Doll uses her charm and wits to get Killer Croc to see a different side of life. It could involve her helping him to overcome some of his more violent tendencies while he protects her from other threats in their world.
One idea could be that they team up to take on a common enemy in a post - apocalyptic world. Their relationship starts off rocky but as they face challenges together, they develop a deeper bond. Maybe Eyeless Jack has some hidden powers that Jeff discovers during their battles.