The alien species of OmegaOf course there is humans, and if you don't know what a human looks like..I feel sorry for you! XD
1. Turian
2. Quarian
3. Asari
4. Drell
6. Salarians
7. Krogan
8. Geth(More Robotic then Aliens, but different species nonetheless]
9. Reapers[Enemy]
----
The rest is here, if you want a picture please ask me!
http://en.wikipedia.org/wiki/Races_of_the_Mass_Effect_universe