Related to Lise C. Ruud, 'Six Monstrous Pigs: Animal Monsters and Museum Practices in the Eighteenth-Century El Real Gabinete de Historia Natural', in Liv Emma Thorsen, et. al. (eds), Animals on Display. 2013. pp. 15-36.
Description:

'Of all the [pig] monsters offered to the cabinet [de Historia Natural during the late eighteenth century], only one was explicitly rejected. The decision concerned an aborted piglet offered to the museum in 1783 by Paula Montenegro y Palomo.' (25)

Ruud relates how Montenegro y Palomo described the piglet in a letter to the museum as follows:

'two small sows joined together with only one, perfect head, with its two ears, and at the entrance of the neck, the two other ears together. The body, only one, with its two legs on one side, and on the other side the two other ones. Where the body ends, the abdomens deviate and each have their little thighs on each side and their two tiny paws. In the middle of the abdomen is only one tract through which they are both nourished.' (25)