Taxidermy: An Very Unusual Polycephaly Specimen of a Twin Headed Calf, circa 1900, a very unusual specimen of a twin headed brown and white cow calf, 18cm from the wall, width 28cm,

Polycephaly is the condition of having more than one head. Two-headed animals (called bicephalic or dicephalic) and three-headed (tricephalic) animals are the only type of multi-headed creatures seen in the real world, and form by the same process as conjoined twins from monozygotic twin embryos.