You searched for: “syncephalus
syncephalus
Conjoined twins with heads fused into one with two bodies, where there is a single face, with four ears.

This group includes the various types of craniopagus (twins with fused skulls), cephalopagus (twins with heads fused but the remainder of the bodies are separate), and cephalothoracopagus (a twin fetus united at the head, neck, and thorax).