Mildred Hubble

Mildred "Millie" Hubble is a witch, and the best friend of Bella Moonshine, Delilia Chamberlain and Enid Nightshade and she also has a strong rivalry with Ethel Hallow. It is  Hardbroom who calls Mildred ‘The Worst Witch’

Mildred is portrayed by Bella Ramsey.