Tardigrades, not cute but very intriguing

They are not cute:

 Credit: NPS/Diane Nelson 

But they are resilient to almost anything, even surviving in low Earth orbit (that is, outer space!)

Here is a nice youtube video summarizing some data about the microscopic "beast" (sub-millimeter in length):

And for the space thing, the paper is fortunately open sourced:

Tardigrades survive exposure to space in low Earth orbit, Current Biology 2018, V. 18