Spider Woman Strikes Back, The (1946)

Jean (Brenda Joyce) takes the job of caretaker/companion to blind woman Zenobia (Gale Sondergaard.) Also hanging around the house in this horror/western is Mario (Rondo Hatton), a deaf-mute servant who evidently wasn't much help to Zenobia when it came to identifying the source of a noise Zenobia couldn't see. Jean is a little slow in realizing that Zenobia is slowly killing her by taking her blood. Zenobia needs her blood to feed some plants. She uses the blossoms of the plants to make poison to kill cattle in order to drive away the local ranchers so she can buy all the land for cheap.