Monozygotic embryonic twins are classified early in development according to the direction of the embryonic plates as thoracopagus, ischiopagus, omphalopagus and others. The objective of the study was to determine a pathology in a sheep. A case of congenital anomaly of a sheep of 4 months of unborn gestation is presented, with predominance of the male sex, it is about twins with unusual characteristics such as male sex in both sheep. As a result, the conformation of the fetus was apparently normal: apparently normal skull, two ocular orbits, two auricular pavilions, a nasal and oral cavity, at the same time it was observed that at the level of the thorax the union of both bodies (thoracoabdominal) with a single navel, 4 posterior members, 2 anterior members, both of the same sex. In conclusion, it was determined that the pathology is craniothoracopagus in sheep.