We have four chilling tales of women you don't want to cross. Nannie Doss loved her husbands...until she got tired of them and decided to murder them. Baba Anujka, the world's oldest serial killer, used her scientific knowledge to poison her victims. Megan Hess and Shirley Koch were a mother/daughter duo who illegally sold body parts through their funeral home. Georgia Tann, aka the "Baby Broker," ran an adoption agency that kidnapped young children and sold them to wealthy families.