"Holy s**t! It's an actual sheeple! What part of it is human? The face? It's the face, isn't it?" But this deserves some explaining, because what they're doing is kind of amazing, and could save a whole bunch of lives.
The idea is to find another source for transplant organs, so that people don't sit on a long waiting list in hopes that some other person will die with a perfectly intact liver or heart (or whatever) before their own fails. The process they're using at the University of Nevada involves injecting human stem cells into a sheep fetus and no, this does not create a monstrous human/sheep hybrid ready to escape into the countryside and terrorize the, uh, grass.
If you were Saint Augustine, you'd be terrified right now.
Instead, the cells circulate through the sheep's system and alter its liver, heart, lungs and whatever else so that they have some human tissue and thus would (hopefully) be able to be transplanted into some sick kid somewhere.
This isn't just at the test tube stage, either. On a farm right now they have a sheep whose liver is 40 percent human. Since the liver's cells regenerate, that means they might be extremely close to being able to do a partial transplant or repair on a human without drawing from the human liver waiting list. Right now, there are 17,000 people waiting for a liver in the U.S., and they will have to wait around a year to get one ... if they survive that long.
"A sheep liver? I'll eat dung beetles if it means drinking again."