Great article and subject matter you bring up here and also a very very difficult one, because there is so many versions to the annunaki story and a wide range of descriptions as to appearance and actions. The one that I came across from many very credible researchers and experiencers is as follows=

Annunaki was a mixture of human and reptilian, specifically the draconian reptilian royal line(white skinned reptilians) from the Sirius+ Orions constellations. The annunaki were created to be the elite leaders of this Earth realm, the managers of this part of space if you will. Human looking enough to deal with the populace but still very alien, enough to know where there true loyalties lie.
Annunaki were very white almost chalky in skin complexion, very long faces (not like paladians) and tall. This doesn't mean that those annunaki with more alien DNA wouldn't have bird or fish features, which i believe some did. But they could also change there own appearance through use of technology. I believe some of them (not many) are still here as part of the controlling class of earth. There are different factions with some more on the side of light than dark, but in the end all this is a guessing game and I feel the more research I do, the less I know in the end...either way great article!