cephalodiprosopus

ceph·a·lo·di·pros·o·pus

(sef'ă-lō-dī-pros'ō-pŭs),
Asymmetric conjoined twins with the head of the autosite carrying a reduced parasitic head. See: conjoined twins, diprosopus.
[cephalo- + G. di-, two, + prosōpon, face]