Alien, as you call them, lifeforms dwell in countless civilizations all over the Cosmos. Remember the Diamond Light Project. That was orchestrated on Planets assigned to that work.
Anthropology studies beings that live under water, hence the idea of mythical mermaids. There are plant life studies, where they look at where plants would grow successfully to provide adequate food and medicine supplies.
Anything that you could possibly imagine – again, allow your mind to take all this in and you can begin to comprehend the magnitude and majesty of the Creation at large.
The Eternal Life flow with no beginning and no end, from the smallest to the largest aspects, nothing is missed or negated – Everything!
Everything has a Purpose!