title: Mildred Hubble
context: Mildred Hubble is a major character in The Worst Witch children's book series by Jill Murphy. She is the protagonist in all the books. She is friends with Maud Spellbody and Enid Nightshade and has a strong rivalry with Ethel Hallow and Drusilla Paddock.
question: Who is the protagonist of Worst Witch?
answers: Mildred Hubble