Ron is often involved. He's Hermione's husband in many fanfictions, so he'd be there to support her during the birth. Harry might also be present, as he's their close friend. He could be the one to ensure their safety during this vulnerable time. Ginny could be another character, perhaps helping Hermione through the labor process, offering her the kind of female support that's important in such a situation.
Other characters like Ginny Weasley could be part of 'hermione fails' fanfiction. Ginny might be Hermione's confidante when she fails in a relationship, offering advice based on her own experiences. Neville Longbottom could also be involved. He could be in a situation where Hermione fails to recognize his potential or she fails to help him when he needs it most. And of course, the Weasley twins, Fred and George, could be involved. They might use Hermione's failure as inspiration for one of their pranks or they could be the ones to cheer her up in a humorous way after she fails something important.
Draco Malfoy is often a common character. He has a big role as he is one of the prominent Slytherins. Their interactions can range from hostile to friendly depending on the story. For instance, he might initially be against Hermione being in Slytherin but later come to respect her.
Harry Potter could be involved. He might be caught in the middle of Hermione's revenge plan on Ron. He could try to be the peacemaker, but his attempts might backfire, leading to more chaos between the two. For example, he might accidentally reveal Hermione's plans to Ron, making Hermione even more determined to succeed with her revenge.
Harry Potter often shows up. Since he's their best friend, he might be caught in the middle of their divorce, trying to mediate or just being there for both of them. His presence can add a lot of emotional depth to the story as he struggles with loyalty to both Hermione and Ron.
Harry and Ron are likely to be involved. They are her closest friends, and they would surely be there for her during such an important event. They might offer moral support or even help her solve some of the problems related to the test.
Another possible main character could be Draco Malfoy. Given his Slytherin background and the connection between Slytherin and Parselmouths, there could be some interesting interactions between him and Hermione. Maybe they start to understand each other better through their shared connection to Parseltongue.
There could also be some unknown characters in the fanfiction. Maybe a secret society within Hogwarts that has been using the cupboard for their own purposes. When Hermione finds out about it, she gets caught up in their affairs. These unknown characters could be students from different houses or even former Hogwarts students who have come back for some hidden agenda related to the cupboard.
Dumbledore might also be an important character. He is very knowledgeable about the history of magic and could have some insights into Hermione's connection to Merlin. He might support Hermione in her new role, or he could be a bit skeptical at first, but eventually come around. Additionally, characters from other magical schools or creatures from the wizarding world could also play significant roles in the story, adding more depth and variety to the plot.
There could also be other wizarding characters who are either friends or foes in relation to Hermione's adventures with the honey badgers. For instance, a wizard who is an expert on magical creatures might be a side character, helping Hermione understand the honey badgers better. Or, there could be a villain who wants to disrupt Hermione's relationship with the honey badgers for some malicious reason.
There could be Harry and Ron. They might be initially skeptical of Hermione's newfound dragon - taming skills but later become her biggest supporters. They could also get involved in her adventures, like helping her find a suitable place to keep the dragons she tames.