On October 15th of 1888, the following chilling letter was sent to a Mr George Lusk by someone claiming to be Jack the Ripper, along with a small box, the contents of which was later determined to be half a human kidney preserved in wine — Catherine Eddowes, Jack the Ripper's fourth victim, was thought to be the organ's previous owner. According to the note, the remainder of her kidney had been fried and eaten.
(Source: Casebook: Jack the Ripper; Image: George Lusk, via Wikipedia.)
I send you half the Kidne I took from one women prasarved it for you tother piece I fried and ate it was very nise. I may send you the bloody knif that took it out if you only wate a whil longer
Catch me when you can Mishter Lusk