The Worst Witch
Mildred "Millie" Hubble is the protagonist of the series. She is a good-hearted, but bungling young witch-in-training, who never seems to get anything right. She is friends with Maud Spellbody and Enid Nightshade and has a strong rivalry with Ethel Hallow. It is Miss Hardbroom, her potions teacher, who calls her "The Worst Witch".
Wicked Witch of the West
The Wicked Witch of the West is a fictional character created by American author L. Frank Baum as the antagonist in his classic children's novel "The Wonderful Wizard of Oz" (1900). In Baum's subsequent "Oz" novels, it is the Nome King who is the principal villain; the Wicked Witch of the West is rarely even referred to again after her death in the first book.