The main characters can be a couple of mischievous boys or girls. For instance, there could be a boy who is always getting into fights at school and a girl who likes to spread false rumors about others. These characters create the chaos and conflict in the story, and the story usually revolves around how they either change their ways or face the consequences of their actions.
Often, the main characters are the naughty kids themselves. They drive the plot with their bad behavior.
Often, the parents are main characters. They are usually portrayed as loving, caring and guiding figures in the family.
The bad wolf is usually a strong and somewhat dangerous character in the 'bad wolf rose fanfic'. It might have a past that makes it seem menacing. The rose, on the other hand, could be a gentle and fragile being. Sometimes, there might also be other secondary characters like a wise old owl that gives advice to the wolf regarding the rose, or a group of small animals that the wolf has to protect the rose from.
Often, the main character is a young boy who has a rebellious streak. He could be a boy from a normal family who just wants to break the rules.
In big bad wolf kids stories, the big bad wolf takes center stage as the main villain. Then, in the story of the three little pigs, we have the three pigs as the protagonists. They are the ones who face the threat of the wolf. In Little Red Riding Hood's story, she is the main character. She is on her way to visit her grandma when she meets the wolf, and her actions and decisions drive the story forward.
Well, the big bad wolf is a central character for sure. Then there are the three little pigs who build their houses. And of course, Little Red Riding Hood who is going to visit her grandma. Sometimes there might also be a hunter who comes to save the day in the Little Red Riding Hood story.
Santa Claus is always a main character. He is the one who brings presents. Also, the kids themselves are main characters, like the little boy or girl waiting for Santa's arrival.
Often brave, just as Tom in the story who wasn't afraid to enter the magic world through the door he drew. And they are also curious, always ready to explore new things around them, which is shown in many kids' stories where the characters discover something amazing.
Perhaps the main characters are siblings. A brother and a sister who have to face some challenges together. The brother could be the more adventurous one, always getting into little troubles, while the sister is the smart one who figures out solutions. There might also be their pet dog that tags along in their adventures and plays an important role in the story.
Since I don't know the exact story, I can't say for sure. But it could be the 'bad kids' themselves, perhaps a ringleader among them. There might also be some teachers or authority figures who are in conflict with the kids.
The main characters in the 'bad kids go to hell graphic novel' are presumably the children who end up in hell. There might be a mix of different types of bad kids - some who are bullies, some who are thieves, etc. They will probably interact with other characters in this hell, like demons or other strange creatures. Their relationships with each other and how they deal with the situation in hell will form the core of the story.