Princess Magnolia is a character from the children's graphic novel series titled "The Princess in Black," created by Shannon Hale and Dean Hale. She is a young princess who leads a double life, balancing her royal duties with her secret identity as a superhero. When danger arises in her kingdom, Princess Magnolia transforms into The Princess in Black to protect her realm from various threats, including monsters. The series emphasizes themes of bravery, friendship, and the importance of being true to oneself while showcasing the adventures of a strong female character.