Deformed lambs are sometimes born with human-like faces
A truly horrifying lamb was born to a sheep in Nigeria recently, and it has locals in an uproar. The lamb was delivered at a veterinary clinic in Sokoto, a city in northeast Nigera with a population of about 47,000, on January 22nd. The lamb's unusual appearance has led many spectators and religious leaders to believe it is a sheep/human hybrid. So many people thronged to the veterinary clinic to see the "monster" that the Nigerian Security and Civil Defence Corps (NSCDC) had to be deployed to manage and disperse the crowds.
Belief in witchcraft is alive and well in Nigeria, and many Nigerians have made the seemingly logical conclusion that this deformed lamb is the result of the sheep's owner having had sexual relations with his sheep. Religious leaders have called for the man to be put on trial, and some are even calling for his execution. I guess you don't want your sheep to give birth to a lamb with birth defects in Nigeria.
The scientific explanation for the lamb's appearance, as given by the veterinarian who had to remove the fetus by caesarian section, is that it was simply the victim of deformation. The sheep had been brought to the clinic after having been in labor for two days without being able to pass the lamb, which was no doubt due at least in part to the lamb's deformities. And the lamb's appearance certainly would have suffered from the process. (Most sheep give birth to their lambs within a few minutes, or an hour or two at most.)
Truthfully, I don't think this lamb looks all that bad, comparatively speaking. It appears to be bloated, as you might expect. Although the reports don't specify, I assume that the lamb was stillborn, and was no doubt somewhat decomposed. I also assume that its skin color is due to coat color, and that if it had survived it would have been a black and white sheep - not terribly unusual. It's hard to see the lamb's face in the photograph, though.
If this birth defect is convincing enough that the townspeople are calling for the shepherd's execution, then it makes me think that this may be where we get our other half-man-half-animal legends. Other lambs with human faces have been born in the past - in recent history, one was born in Zimbabwe, and another found in Turkey. A stillborn mutant lamb like this could easily have been the source of the legends of Pan, who is depicted as a hairy man with goat's legs.