When I was eight my parents took me to see the classic horror flick Alien in the movie theater. Little did they know what they were getting themselves–and me–into. They were sure I’d be terrified, but I barely flinched through the horror and gore (except for the iconic spaghetti scene, where the baby alien bursts through John Hurt’s stomach).

Maybe that’s because a few years earlier I was terrified by the flesh-eating zombies in George Romero’s Night of the Living Dead–and thus inoculated–from horror.

Nevertheless, the Alien franchise features some of the scariest, awe-inspiring monsters. These are creatures that use humans not for food but as breeding pods, suffering through slow, agonizing deaths. Very much an H.P Lovecraft view of horror: the alien monster as a destroying force that gives no consideration to our humanity in pursuit of its destruction.

It turns out, once again, that nature parallels these horrors.

Take this parasite called Phironima. According to this article, it is thought to be the inspiration for the Alien monster.

And with good reason.

This tiny parasite lives in the ocean. It survives and thrives by attacking free-floating zooplankton. First it carves out the zooplankton’s insides. Then it climbs in and uses the hollowed out creature as its transport.

It’s not clear whether the Phironima kills the zooplankton, but the parallels to the Alien xenomorph are blood-curdlingly clear: a monstrous-looking creature alters and destroys another to use for its own benefit.

This is nature.