How will you say hello or shake hands?
Relax... this is not an alien but a species from our own planet.
The individual above is called Tardigrade and is 0.5mm in length. But it is notable for some other reasons.
Tardigrades are some of the most resilient animals: they can survive extreme conditions that would be rapidly fatal to nearly all other known life forms. They can withstand temperature ranges from −272 °C to 150 °C, pressures about six times greater than those found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than the lethal dose for a human, and the vacuum of outer space. They can go without food or water for more than 30 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce.
Read more about tardigrades here.