This Halloween, meet… THE BLOB!

On one hand, defining a living thing seems pretty easy.

Rocks? Not a living thing. Dogs? Very much a living thing. (Down, Sparky!)

Plants and fungi generally don't move around, but they obviously grow.

Living things, easy to define. Case closed.

Except...

Science is actually full of examples of things that defy easy categorization. For example, are viruses living things? What type? Which brings us to one of the strangest examples of just how bizarre life can get.

Happy Halloween, everyone! It's time for you to meet... The Blob.

Movie monster?

Two separate 'islands' of this slime mold reach out and join together. (Wikimedia Commons)

This vivid yellow living thing went on public display for the first time at the Paris Zoological Park on October 19. It goes by the name of Physarum polycephalum (say FIH-sah-ruhm pah-lee-SEH-fah-luhm), but many have taken to just calling it The Blob. And while we don't expect it to devour a town as happened in the classic 1958 horror film, The Blob, we do see the connection.

This thing is a collection of unicellular organisms (this means that on a basic level they are made up of many of the same cells — humans are multicellular and made of thousands of different types of cells). Kind of like a movie monster, The Blob can function as many smaller pieces or join into a larger whole. It can even move in search of food, though this happens very slowly. Sound kind of creepy?

But maybe the most bizarre thing about it? Like a lot of monsters and aliens in films, we don't know exactly what it is.

Animal? Or fungus?

Physarum polycephalum has no brain, eyes, or mouth. So it's a fungus then, right? Like mold you'd find in a basement or fungi growing on a tree. Sure, but...

There's that whole moving thing! And it can digest food, heal itself when cut, and react to stimuli (such as heat or light). AND... it can learn. Okay, we're not saying it can go to class or anything. But it is able to adapt its behaviour after encountering certain situations. And when two sections of The Blob join together, the learning of both sections is passed into the entire new creature.

Not an animal nor a plant nor a fungus. Whoa.

Last-minute costume?

So what are we saying here? Physarum polycephalum is one fascinating... thing. And if you're still looking for a great Halloween costume, might we suggest covering yourself in a bunch of yellow goo and going as The Blob!

Just make sure it's not, like, the actual blob... AAHHHHHHH! IT'S TAKING OVER MY BODY!! HELP!!

(Just kidding! The Blob does not attack humans! Watch the video about it below. We think it's super neat!)