- Sphinx, jackalope, manticore, griffin, hippogriff.

All monsters made up of body parts from more than one animal.

We now call these hybrid monsters chimeras, owing to the original Chimaera of ancient Greece, a ridiculously impractical mythological monster with three heads, a lion, a goat, and a snake.

Which seems absurd, but then again, humans have been crafting these mythological creatures for thousands of years, in more ways than one.

I'm Dr. Emily Zarka, and this is Monstrum.

When I say humans have crafted chimeras for thousands of years, I mean handcrafted, as in sewing dead bodies together.

The ancient Romans displayed a centaur preserved in honey.

The figure was likely made from mummified human and horse remains.

The Romans also exhibited a puppet with a false human head attached to a large serpent that could open and close its mouth and flick its snake tongue.

It fooled quite a few people.

And don't even get me started on all the weird taxidermy trends in the Victorian period.

But it's not all jumbled up animals and antlers glued to rabbits.

A real, living chimera of a sheep and a goat, a geep, was made in the 1980s.

Now, I could try to explain all of this and do a terrible job at it, but I'll turn to the esteemed Dr. Joe Hanson.

Joe, could you help me out here?

- Okay, maybe you've heard of ligers, mules, beefalos, zonkeys, coydogs, wholphins, or maybe pizzly bears.

Those are all real examples of two animals combined into one, but they're not chimeras, biologically speaking.

They're hybrid animals, one embryo that came from two related species mating, like a lion and a tiger.

But the geep was different.

That started as two embryos, one goat and one sheep that were combined to make one geep embryo.

Two bodies, or embryos, combined into one is a chimera.

Science.

- So scientists refer to these animals as chimeras, a concept with its roots deep in mythology.

Mythical hybrid animals have existed in cultures around the world for centuries.

It wasn't until Homer's Iliad that the word Chimaera first appears.

Here, the Chimaera is a female beast with the upper body of a lion, the tail of a snake, and a goat head in the middle of its torso.

A fire-breathing goat head.

Yeah, it has three heads and the goat is the most threatening one.

(goat bleating) In the story, Bellerophon is ordered to kill the Chimaera, a seemingly impossible task.

Luckily for our hero, his noble steed is none other than the winged horse Pegasus, which helps him kill the Chimaera from above.

Pegasus, also a chimera.

Lowercase C chimera.

Go figure.

After Homer's tale, other Greek writers followed with their own versions of the Chimaera story.

Most set Chimaera's home in Lycia, 500 long miles from Athens, a metaphor for the Greeks' fear of the foreign and what they saw as uncivilized territory.

It's also a place known for mysteriously burning ground fires caused by natural gas leaking to the surface.

But to humans of the time, a fire-breathing goat was just as likely.

The mountain where these fires burned was appropriately called Mount Chimaera.

So how the heck do we explain the inspiration for the lion, goat, serpent heads thing?

- We don't see cross species animal chimeras in the wild.

But we do sometimes see certain traits on one species that kind of appeared to come from other species.

Like, extra limbs, or how some humans have extra fingers that make them look kinda reptile-y?

And during development, many vertebrate embryos pass through stages that resemble more ancient branches of life, like fish, complete with gill-looking growths.

So that would be confusing in olden days.

And finally, some animals can be born with multiple heads, though they're always the same kind of heads.

So you pretty much gotta stretch the scientific truth to get mythical chimeras.

- One explanation for the creation of this odd three-headed creature might come from human confusion of early fossil discoveries.

It's possible that the fossilized bones of a goat, a lion, and a snake could have been found in the same place when they were killed by a flash flood or fell into a tar pit.

Humans discovered their fossilized remains together and imagined a chimera to explain what they saw.

There is a ton of ancient art that depicts the chimera.

Everything from coins and statutes to containers and plates.

Because of its presence in the Iliad and other classical Greek texts and art, the chimera continued to be a recognizable myth as the centuries wore on.

The word chimera came to signify not just a hybrid animal but any thing that seemed to be impossible or a figment of the imagination.

Only over the last few decades have we been able to accept and prove that inter-species chimeras are possible.

After the geep, another crazy moment in chimera history happened in 1998 when two scientists tried to get a patent on a variety of human-animal chimeras.

And yes, they use that term specifically.

The patent was rejected as an invention that would be injurious the well-being, good policy, or good morals of society, and the US Patent and Trademark Office commissioner reportedly even referred to these proposed creations as monsters.

- But research into human-animal chimeras continues.

Some scientists are growing human tissues inside pigs in order to one day improve how we transplant organs.

But the ethics and feelings surrounding this kind of research are complicated.

I mean, in a world of human-animal chimeras.

- What constitutes a human?

If I grew bird wings, would I be considered a human or a chimera?

As technology advances, the possibility of even human chimeras becomes real.

The world of biological chimeras is even weirder, so head over to It's Okay To Be Smart and watch Joe's video to learn about that.

So we've come full circle.

From the impossible chimera monster of Greek mythology to the potential for real animal chimeras.

When we move from the realm of fantasy into reality, things get much more complicated, so it's no longer just an exercise of imagination but a question about ethics.

We can craft chimeras, but should we?