There might be a 'Avengers Feral Child Fanfiction' where the feral child is actually from another dimension. The Avengers find the child and have to figure out how to take care of them while also dealing with the threats that come with the child's other - dimensional origin. This could involve battles against strange creatures that are after the child.
One interesting 'Avengers Feral Child Fanfiction' story could be about a feral child with superpowers being discovered by the Avengers. The child might have unique abilities that are both a mystery and a potential asset to the team. For example, they could have an uncanny sense of danger or be able to communicate with animals in a way that helps the Avengers during a mission.
One interesting 'feral child Harry Potter fanfiction' could be about a Harry who grows up in the Forbidden Forest, learning magic from the creatures there. He might have a unique bond with the centaurs and use their ancient magic knowledge in ways not seen before in Hogwarts. Another could be where he's raised by magical beasts in a hidden part of the grounds, and when he finally enters Hogwarts, he has a wild and untamed approach to magic that both confounds and amazes his professors.
Obviously, the Avengers are main characters. This includes Iron Man, Captain America, Thor and others. They are the ones who usually find the feral child and get involved in the child's story. The feral child themselves is also a main character. Their backstory, their powers or lack thereof, and their personality all play important roles in the fanfiction.
The story of Genie is also somewhat of a 'feral child' scary story. Genie was a girl who was severely neglected and isolated for most of her early life. When she was discovered, she was in a very pitiable and almost 'feral' state. She couldn't communicate properly, had no social skills, and was extremely underdeveloped. It was scary to think about how human beings could be reduced to such a state through such cruel treatment.
One interesting 'Harry Potter' feral fanfiction could be one where the characters are transformed into their animal forms more often and have to navigate the wizarding world in that state. For example, Harry as a stag having to outwit Death Eaters in the Forbidden Forest.
A really cool Percy Jackson feral fanfiction idea could be that Percy discovers a hidden part of the world where feral demigods exist. These demigods have lived away from civilization for so long that they have become more like wild animals. Percy has to learn their ways and find a balance between his normal self and this new feral side he discovers while trying to help these forgotten demigods integrate with the rest of the demigod community.
One interesting OC feral mutant fanfiction could be about a new mutant who has the ability to transform into a feral beast with unique powers. They might struggle to control this side of them while also trying to fit into a world that fears mutants.
One great example could be those that explore Naruto's growth from a 'feral' state. In some fanfictions, Naruto might be more in tune with his animal - like instincts at first. For instance, he could be shown to have an acute sense of smell or hearing that he uses to his advantage in the ninja world. Another example might be a fanfiction where Naruto's 'feral' nature makes him more of an outcast among the villagers initially, but then he gradually overcomes this through his relationships with his friends like Sasuke and Sakura. There are also fanfictions that play with the idea of Naruto having a more wild fighting style due to his 'feral' upbringing, which makes for some really interesting battle scenes.
One interesting idea could be Naruto growing up in the wild and having a more primal connection to nature. Maybe he has unique combat styles that are based on animal instincts.
One interesting 'Avengers child weapon' fanfiction could be about a young hero who discovers an ancient weapon and the Avengers have to help them understand and control its power. Maybe the child is related to one of the Avengers in some way, like a long - lost descendant.
One interesting feral animal transformation story is the werewolf legend. In many cultures, it's believed that a human can transform into a wolf - like, feral creature under certain conditions, like a full moon. Another could be the stories of selkies in Celtic mythology. Selkies were said to be seals that could transform into humans. They often had tales of love and loss associated with their transformations between the two forms.