pygomelus

pygomelus

 [pi-gom´ĕ-lus]
a fetus with a supernumerary limb or limbs attached to or near the buttocks.

py·gom·e·lus

(pī-gom'ĕ-lŭs),
Unequal conjoined twins in which the parasite is represented by a fleshy mass, or by a more fully developed limb, attached to the sacral or coccygeal region of the autosite. See: conjoined twins.
[pygo- + G. melos, part]