Question

Is there any living organism below -20 degree?

Answer 1

A simple search talks about Xanthoria elegans, a type of lichen.

Explanation:

I will explain briefly about this organism. This organism is a lichen, and is therefore very small. Not many other organisms can live below `-20^@"C"`, and all that can are microbial. This special lichen can even photosynthesize at `-24^@"C"`.

Such organisms that can live in thes cold temperatures are called psychrophiles. Read more at:

https://en.wikipedia.org/wiki/Psychrophile