In 1983, on the frozen tundras of Antarctica, Scientists collected a sample of moss. Now initially, this seems like no big deal—their original intent was to study the plant itself, but what they found inside the plant was a world teeming with life.

The plant contained samples of Tardigrades (otherwise known as water bears). These curious, microscopic creatures have been attracting a lot of attention lately, for good reason. For one, they are ridiculously good-looking—resembling cute, chubby, caterpillars. Their bizarre appearance was practically made for the Internet. Just look at them!

Notice a resemblance?

Their rise to stardom happened after scientists sent them to space, expecting them to die. But no, these low-profile, modest creatures blew our minds by surviving the vacuum of space—the only known animal to do so. Tardigrades are tough, little bastards.

Back to the moss sample. It was brought back to Japan where it was kept frozen for 30 years at -20 degrees Celsius. The poor moss sample was ignored and forgotten for decades.

Then, in 2014, scientists at Tokyo’s National Institute of Polar Research unfroze the sample which contained the frozen bodies of two tardigrades and one tardigrade egg. Miraculously, one of the tardigrades came back to life. Like a Frankenstein’s monster of microscopic creatures.

As far as the egg? It hatched, and after 30 years, a tardigrade was born. The revived tardigrades even went on to lay eggs of their own, which were found to have no deformities.

Here’s a video of the Antarctic samples coming back to life:

How are they able to do this?

Tardigrades are extremophiles, meaning they could survive a whole bunch of things that could kill weak humans like radiation, boiling hot temperatures, and freezing temperatures.

Whenever they find themselves in unwelcoming environments, tardigrades enter suspended animation by drying out and turning into a lifeless ball. To protect their bodies, they coat themselves with bio-glass. You can read more about it here.

In this state, they don’t eat or drink. Think of the sleeper ships in Star Trek. Whenever tardigrades reenter water, the glass melts and they are revived again to resume their normal day-to-day activities (like eating moss).

Here’s the catch: The longer they’re in this state of suspended animation, the more difficult it is to revive them. Scientists estimated that tardigrades could possibly survive for decades, but before the Japanese study published this week, the longest a tardigrade was observed to survive suspended animation was nine years.

You can see why these resilient little guys are such an interest to scientists: surviving suspended animation for 30 years is a pretty big deal.