Microscopic, bear-shaped animals called tardigrades are one of the most resilient animals on earth. Known colloquially as water bears, they can survive freezing temperatures, radiation, even a trip to outer space.
The creatures are famous for their ability to withstand extremely dry conditions. Water bears can go without water for 10 years, surviving as a dessicated shell. Just how they come back to life when their environment is friendlier has baffled scientists for years.