Alien invasion

These grotesque aliens creeping toward my lens are lichen colonising the bark of a tree. This one is called Cladonia Humilis.

Info :
Lichens are widespread and may be long-lived, however, many are also vulnerable to environmental disturbance, and may be useful to scientists in assessing the effects of air pollution, ozone depletion, and metal contamination.
Lichens have also been used in making dyes and perfumes, as well as in traditional medicines.