Mona is a student in the School for Evil. She is the daughter of the Wicked Witch of the West, also known as Griselda of Ravenbow.
She was in both the School for Girls and the School for New Evil along with the rest of the Nevergirls, bar Sophie.
In the books, she is described as being tall, with "sickly green skin." In her portrait in the Ever Never Handbook she is drawn with black hair.
Mona is on track to become a mogrif, a jellyfish, and her fourth year quest is to kidnap Missou, the fabled seer of Rainbow Gale, and force him to reveal prophecies about Evil's defeats so they can be prevented.