11. Miss Minchin (Eleanor Bron) in 'A Little Princess'

The mistress of a posh New York boarding school for girls, Miss Minchin at first appears to be the picture of motherly concern toward her young charges. When Sara (Leisel Matthews) is orphaned and penniless, however, Miss Minchin reveals her cruel, true nature. She forces Sara to work for her keep and refuses to let her even talk to her former friends. Worst of all, when Sara's father miraculously reappears, Miss Minchin nearly prevents his reuniting with his daughter. Boo, hiss!