It may look like an ordinary microscopic organism but a tardigrade is the most 'indestructible' animal on Earth.
Tardigrades, sometimes called water bears, can survive up to 3 decades without food, live in volcanoes and endure the vacuum of space.
Measuring from 0.1mm to 1.5mm, this tiny creature is practically invisible to the naked eye and has survived for hundreds of millions of years.
As a matter of fact, scientists believe they have survived all major extinction events on Earth, including the one that led to the extinction of the dinosaurs. Only the eventual death of the sun may be enough to wipe out the tardigrades. Then again, we don't really know for sure.