Meet the Tardigrade, or commonly called the “water bear” because of the similarities in the way they walk—it resembles the gait of a bear. It is the toughest living creature on earth, yet it’s microscopic.
Tardigrades are able to withstand 5,000 gamma rays of radiation, temperatures from 304 °F to near absolute zero, and ten years without water. Furthermore, they are able to live and reproduce in the vacuum of outer space, and they can hibernate indefinitely. [source]