There could also be long - term consequences for his superhero career. He would miss out on all the development and growth that he had been going through as an adult superhero. When he eventually turns back (if he does), he might have a hard time catching up on all the things that happened while he was a baby, both in terms of his relationships and his understanding of the ever - changing threats in the city.
His identity might be at risk. If people find out that Spiderman has turned into a baby, it could expose his secret identity. Also, his friends and family would have to take on new roles. For example, Aunt May would have to be more of a caretaker than ever, and his superhero friends would need to protect him from villains who might see this as an opportunity to get rid of Spiderman once and for all.
Well, in a fanfiction, it could be due to some sort of magic spell gone wrong. Maybe a villain was trying to defeat Spiderman in a new and unique way and accidentally turned him into a baby. Another possibility is that some strange scientific experiment in the Marvel universe backfired on him.
Well, he would lose his human form and all the abilities that come with it. He would have to learn to move and hunt as a basilisk, which would be a huge adjustment. His friends might not recognize him and could even be afraid of him.
In the Hogwarts hierarchy, things would change. Hermione is often seen as a bit of an outcast by some Slytherins because she's a Gryffindor. Draco, now in her body, would face a different kind of discrimination or at least a lot of strange looks from his own housemates. He would also have to deal with Hermione's reputation among the teachers. Some teachers might expect the same level of knowledge and participation from 'Hermione' (who is actually Draco), and he would struggle to meet those expectations.
In this fanfiction, it could be that Hinata's memories are still somewhat intact even as a baby. So she might still show signs of her shyness towards Naruto. She could blush when Naruto gets close to her while taking care of her. And perhaps, this situation could lead to Naruto realizing his deeper feelings for Hinata in a more protective and caring way. He would start to see her in a different light and understand how important she is to him on a whole new level.
Well, in the fanfiction world, if Snape turns into a baby, it could be really chaotic. His colleagues at Hogwarts might be extremely shocked. Maybe Dumbledore would have to take on the role of caretaker, trying to figure out how to reverse the spell. And Harry Potter would probably be very confused seeing his former strict professor as a helpless baby.
The plot could be centered around the chaos that ensues when Itachi turns into a baby. His enemies might see this as an opportunity to attack, thinking he's vulnerable. However, his allies would protect him. And as they take care of him, they might discover new things about Itachi's past or even his true nature that was hidden before. There could be many comical scenes like when they try to diaper him or feed him baby food and he makes a fuss.
Well, in this kind of fanfiction, probably his friends would be super shocked at first. They might struggle to take care of him as he's now a baby. His powers could also be affected in some strange ways, like they might be uncontrollable or show up in unexpected forms since he's in a baby's body.
In the 'ichigo turns into a baby fanfiction', his relationships would change significantly. For example, Rukia might take on a more motherly role towards him. His friends would be very confused at first but then would do their best to keep him safe and figure out how to turn him back. Also, his enemies might see this as an opportunity to finally get rid of him, but his friends would surely not let that happen.
Perhaps in the fanfiction, Annabeth turning into a baby could be part of a magical curse. Her friends would then embark on a quest to find the antidote. Along the way, baby Annabeth could display some of her old characteristics in a cute, baby - like way. For instance, she might still show an interest in architecture by babbling when she sees grand buildings.
In such a fanfiction, there could be a lot of chaos. Maybe Harry and Ron would be completely clueless on how to take care of baby Hermione. They might struggle with simple things like feeding her or changing her diapers. It could also be a really cute scenario where they try their best to protect her in this vulnerable state.