Black Widow Tillie Klimek (Unabridged‪)‬

Ottilie "Tillie" Klimek - born Ottilie Gburek - was a Polish American serial killer who was active in Chicago during the early 1900s. She allegedly murdered between six and 20 individuals by poisoning them with arsenic. Additional victims included her other husbands, a boyfriend, relatives, and various neighbors with the help of her cousin Nellie Koulik.