Winifred Gillyflower
From Tardis Wiki, the free Doctor Who reference
Winifred Gillyflower was a mentally unstable old woman; she founded the dystopian society of Sweetville. Her instability was caused by her blaming her husband for her daughter's blindness, when in truth it was Winifred who experimented on Ada. Winifred allowed a red leech she nicknamed Mister Sweet to live on her chest, feeding on the nectar of Winifred herself. She planned to poison the air with Mister Sweet's own poison. The Eleventh Doctor, Clara, Madame Vastra and Jenny Flint successfully stopped this plot, and Strax killed her. (TV: The Crimson Horror)
