Jack and Annie are definitely among the most popular. Since they are the main characters in the original series, they often take center stage in fanfiction too. Morgan le Fay also shows up a lot as she has that mysterious and magical allure.
Well, Jack and Annie are the obvious popular ones. Their personalities and the way they grow throughout the original series make them great characters for fanfiction. But aside from them, Merlin is also a very popular character in Magic Tree House fanfiction. His powerful magic and his role as a guide in some of the adventures give a lot of scope for fanfiction writers to explore different storylines. Also, the various historical figures that Jack and Annie meet during their travels can also become popular in certain fanfictions, as they bring a touch of authenticity and historical intrigue to the stories.
Harry Potter himself is often a popular character in such fanfic. His magical abilities and heroic nature make him a central figure that can easily be incorporated into the Magic Tree House adventures.
Dobby is definitely one of the most popular. His character from the original books was so endearing and his actions so brave that he often features prominently in fanfiction. Another popular one is Kreacher. His complex relationship with the Black family and his growth as a character make him a great subject for fanfiction writers.
In the 'magic tree house the graphic novel', the two central characters are Jack and Annie. Jack is a boy who loves to read and learn. His knowledge comes in handy during their adventures. Annie is his sister, who is brave and eager to explore. They both enter the magic tree house, which transports them to amazing places. Their different personalities create an interesting dynamic as they face the challenges and wonders of the different worlds they visit.
Jack and Annie are the main characters in 'the magic tree house graphic novel'. They are siblings or at least very close friends. They are the ones who enter the magic tree house and embark on all those amazing adventures together.
Chowder is also well - liked. His comical nature gives writers a lot to work with in terms of adding humor to their stories.
Definitely Daemon Targaryen. He's so mysterious and has this alluring, dangerous quality about him. Writers love to play with his character, creating different scenarios for him. Rhaenyra is also up there. As a central figure in the show, fanfiction often delves deeper into her emotions and her journey. Then there's Viserys. Some fanfictions explore his character more in - depth, especially his earlier days and the decisions he made that led to the events in the show.
Naruto himself is often very popular in these fanfictions. After all, it's his house. Writers love to explore his daily life in the house and his interactions with friends and family there.
Zoey Redbird is often a very popular character. She is the main character in the original series, and in fanfiction, people like to explore her story further, maybe give her different challenges or different romantic interests.
Darth Vader is also a favorite. His complex relationship with the Force, being both a powerful Sith and once a Jedi, offers a lot of room for creative exploration in fanfiction. Maybe in some stories, he has a different redemption arc due to some unique'magic of the force' element.
I'm not sure exactly who the main characters are without reading the story in detail, but usually in a Magic Tree House story, there are Jack and Annie. They are often the ones who go on adventures in the magic tree house.