Blanche Dumas was born on the Caribbean island of Martinique in 1860, to a French father and a biracial mother. She had a third leg attached to her sacrum, and her two primary legs were said to be imperfectly developed. The third leg was without a mobile joint but had a bend in it where the knee would have been. Her pelvis was wider than normal and she had double genitalia as well as a duplicate bowel and bladder. To the right of her middle leg was the stump of another limb; it's unknown at this time whether this stump was naturally occurring or the site of a surgical amputation, but promoters sought to maximize its appeal by adorning it with nipples and advertising it a pair of "well-formed" extra breasts!
Stories of Blanche all mention her pronounced libido. She moved to Paris later in life and became a courtesan, and allegedly, upon hearing about the three-legged man, dos Santos, who was touring at the same time, she expressed a desire to have sex with him. According to Gould and Pyle, "There were two vaginae and two well-developed vulvae, both having equally developed sensations. The sexual appetite was markedly developed, and coitus was practised in both vaginae."
Left: Rare photo of young Blanche Dumas, clearly showing her undeveloped (or amputated) fourth leg. Right: Adult, sexualized Blanche with nipples painted on her leg stump. This is the basis for the woodcut above. Both photos submitted by an anonymous reader.