Well, in a Draco - turned - into - a - kid fanfiction, perhaps it's part of a dark magic experiment gone wrong. As a kid, Draco might be more vulnerable and open. This could lead to him being protected by characters who were once his enemies. For example, Harry Potter might feel a sense of responsibility to keep this young Draco safe from the dangers of the wizarding world that a child shouldn't face.
In such a fanfiction, it could start with Draco waking up one day as a kid, completely bewildered. His family, especially his father, would be in shock. Lucius might be forced to confront his parenting in a different way as he tries to deal with a child - like Draco. Meanwhile, Draco's transformation could also be a catalyst for change in Hogwarts. Teachers might treat him differently, and students might have mixed reactions. Some might bully him, while others might show him kindness, which would be a new experience for Draco.
One possible plot could be that Draco is turned into a kid by a misfired spell. His friends, who are used to his haughty self, now have to deal with a cute, innocent, and sometimes clueless kid - Draco. They might start to see a different side of him and form new bonds as they try to figure out how to turn him back.
Perhaps it's a prank gone wrong. A group of Gryffindors, thinking they could teach Draco a lesson, cast a spell on him that they thought would just embarrass him. But instead, it turns him into a baby. Now, Hermione, being the brilliant witch she is, feels responsible for finding a cure. She starts researching in the library, while Ron is left to keep an eye on baby Draco. Ron has no idea how to take care of a baby, and there are lots of comical moments as he tries to feed Draco and keep him from crying.
One possible plot could be that Ochaco wakes up one day as a kid and has to figure out how to reverse it while also dealing with her now child - like body. She might struggle with her hero training as a kid, like not being able to reach high places or lift heavy objects like before. And she could have cute interactions with her classmates who are now much bigger and older - looking compared to her.
One possible plot could be that Black Widow, while on a mission, gets hit by some sort of experimental weapon or magic spell that reverts her to a child. She then has to rely on her Avengers teammates to protect her while they search for a way to reverse the effect. Her skills as a child would be limited, but her intelligence might still be intact, leading to some interesting situations where she tries to communicate complex ideas in a child's body.
He'd probably be more innocent. The snobbish and often cruel Draco we know would be replaced with a more naive and curious version. He might not have the same prejudices as he does as a teen or adult.
Well, he might lose all his evil cunning at first. Since he's a kid, he could start to see the world in a more innocent way. Maybe he'll make friends with people he used to terrorize, not realizing who they are. And he could be easily influenced by good-hearted characters, starting to develop a sense of right and wrong that's completely different from his adult, villainous self.
One possible plot twist could be that Draco, after turning Harry into a girl, starts to have feelings for this new version of Harry that he didn't expect. He might struggle with his new - found emotions as he was previously an adversary. Another twist could be that Harry, as a girl, discovers new magical abilities that were dormant before. This could change the power dynamics in the wizarding world. And perhaps, the whole Hogwarts community has to adjust to Harry's new gender, which could lead to both humorous and serious situations as people's preconceived notions are challenged.
It could be an old rival of the Malfoy family. Maybe a wizard whose family was wronged by the Malfoys in the past. This wizard has been biding his time, waiting for the perfect opportunity to strike. Turning Draco into a baby is his way of getting revenge on the family, making them look weak and powerless.
Maybe it could be about how Draco's slobbish habits annoy his friends or family in the fanfiction world. For example, he might leave his things all over the place in the Slytherin common room, causing chaos and getting into little squabbles with his housemates.
It could be about Draco having some deep self - reflecting moments while in the shower. Maybe he's thinking about his past actions at Hogwarts and how he wants to change.
One possibility is that the kid has to deal with the prejudices from both the Gryffindor and Slytherin sides. Since Hermione is a Gryffindor and Draco is a Slytherin, their child might be caught in the middle of the long - standing rivalries between the two houses.