Any conversation about the most notorious serial killers in the world is incomplete without a mention of Mary Ann Cotton, an Englishwomen, whose killing spree constituted of her own husbands, a lover and several children. Her reign of terror stretched for 21 years and her total kill count is the same. Her weapon of choice was poison, arsenic to be more precise, which produced symptoms similar to an upset stomach, and that enabled her escape the eyes of law for two decades. She had a string of husbands in her life, and she killed mostly for the insurance money. She lured in men through her charm and beauty and married mostly the rich ones. Once tired of them, she would casually slip poison in their food or drinks and escape with the insurance money without arousing suspicions. In the later years of her killings, her heightened over-confidence made her blatantly kill more people, and eventually, someone grew suspicious of the fact that wherever she went, people were dying of the exact same cause. The murder of her stepson, Charles Cotton, from her last marriage finally got her in the prison and when the world heard the tales of her creepy life, people were shocked and dismayed. She was hanged until death in 1873.