Sgt Clifford Stone (1st class with US Army) came forth in 2010 as part of the disclosure project stating that he worked on the recovery of crashed extra terrestrial craft and that by 1989 they had cataloged 57 separate species of extra terrestrial beings. He went on to add that for the most part all of these beings were humanoid in appearance, which raises some very interesting questions if this information is accurate.
I certainly think that the 'gray' aliens depicted in modern day science fiction is certainly one species that is out there. Karahunj Armenia has stone carvings depicting 'grays', cave paintings in Kimberly Australia also depicting 'gray's. Even in ancient literature there are descriptions (In the Mahabharata) of divine beings with large black eyes shaped like lotus petals; there are over 250 descriptions like this in The Mahabharata. And this is only the tip of the iceberg!
The lack of evidence isn't absence of evidence, it is evidence that has been denied to all