Yes Entons are inspired by the greys ;)
I didn't know anything about the Annunaki alien theory, so I can't say the Keskudons were inspired by that. I just came up with the idea of a race who enslaves everyone because they had once owned this galaxy and saw everyone else who had evolved and advanced after them as just weeds getting in the way. After all the Galaxy is pretty damn old, life might have found a way even if the Galaxy would have been a less hospitable place for us.
Tairoshans were inspired by the idea that our morals come from our own evolution and what benefits us and a race with a different evolution background would perhaps have completely different morals and would judge others based on it. Through previous modding I realised that it would be interesting to do races that got on with everyone or were hated by everyone, this was the basis for coming up with ideas for the Tairoshan and Keskudon.
The Lipids were just an idea that a parasite doesn't always do harm and that life lives in harmony with some parasites. It would be an evolutionary benefit if a parasite was desired because of it's benefits. I had this idea how important is happiness because it is something we always search for, I imagine something like them may actually be chosen by a lot of people on this planet. The picture makes them look a lot more grim than I intended but I was lacking options.
The Visareen inspired by certain countries east of me on the planet.
Phaerax I wanted a much more alien alien, like how some insects are bizarre to us. I developed on how some animals can 'see' things we can't using sound, or hear things we can't, what if they evolved a way to use micro waves.
The Riktoh by the gold rush period in America.
The Jintus by a friend I had as a youth who liked to stir trouble then stand behind other friends who were twice his size in height and let them deal with it. It was pointed out to me that the Jintus are mentioned in the help files so I had to come up with a background for them.
The Napoar because I was curious about the idea of consciousness, and if we replaced parts of our brain with machine would we still be us? Is it possible to maintain our 'selves' if we entirely replaced the brain with mechanics of similar function. Also I notice in people behaviours and personality traits that are so obviously caused by our instincts, I wondered what we would be like if we removed instincts out of the equation.
The Caleph because I thought 3D space navigation would be quite a skill and what if a creature did that naturally they would be amazing at it. The idea taken from Starbase Orion on the iPad.
The XHumans because I was always curious what would happen if humans had some form of speciation and what this would do to us.
The Ortain because it was an idea of entirely AI robots which we created in our own image. And then I had the idea that if we did that and for some reason got wiped out it would be curious if we had created them to the extent to be self sufficient.
Paratis inspired by Keterovs mostly, I wanted a similar race for the insects.
The Tarapin inspired by how some race minorities were treated in the past but please don't look at racial characteristic and think I mean anything by that. I just designed an alien with similar background.
Lemeresh were inspired by how one of the races was introduced in Babylon 5, I forget their name and haven't seen all the series so they were inspired by them to a point.
Yor I wanted space cockroaches and were inspired a bit by 80s video game aliens.