I suppose I will look at the similarities with the alien. It is a homologous structure with other species here on Earth. It appears to have very similar arms, legs, and head like a human. I suppose maybe this species may have a common ancestor with us humans and primates. Presumably if this is so, then it has gone through several stages of evolution over time. It has two more eyes, a flappy horn, and pointy ears. To say the least, it has adapted to it's environment. Although, we don't know if it is a permanent inhabitant of the moon.
If I draw a cladogram...
Squirrel Monkey
Gorilla
Chimpanzee
Human
No tail
Alien
Downward-pointing nose
Flat foot
Horn, two eyes, pointy ears
This alien's species would go right above the humans.
This just shows these aliens have advanced far more than us. We know that this alien cannot be analogous to humans because this alien's species is from a common ancestor, and has a very similar structure. Furthermore, we can rule out that this is probably not convergent evolution, since the evidence shows that they have a common ancestor. It is most likely that the alien's species is going through divergent evolution, because they have homologous structures.