I've only been to 5 or so planets/moons so far but one of them had no animal life and very little plant life. It had a very thin atmosphere, which caused my life support to work harder and run out faster. Lots of plutonium, some iron, and not much else that I saw.

My two most memorable creature encounters :

A thing that looked a lot like an Ewok. When I scanned it, it's behavior was described as Unpredictable. It attacked me seconds later, running and jumping up at me with claws and teeth bared… or maybe it was a beak… not sure. The main thing I found cool about this encounter was that it was the only creature of it's type that I saw on that planet.

I also found a moon with very little life, but what it had in abundance were these little crab looking things that traveled in packs of 5 or more and were very aggressive. More than once I had to run, jump on something out of their reach, and shower them with grenades. The Sentinels loved that, lemme tell ya.

Yeah I found a funny looking thing that had a head like a rhino, a shelled torso like a turtle, legs that were sort of elephant like, and these little green butterfly wings that were somehow keeping it in the air.

This thing was the size of my ship, by the way.

Love this game!