Sylvia Thaw
From Tardis Wiki, the free Doctor Who reference
Lady Thaw assisted in creation the rejuvinating device used and built by Richard Lazarus, she had intended to use it for herself. She was killed by Lazarus when he mutated as he needed the energy for the mutation to stabalise as the Doctor described it she had had the very life energy sucked from her.(DW: The Lazarus Experiment)
