I'm going to go with the biology as described on the old 80's UFO CoverUp Live show..(spare me the Strawberry Ice Cream comments please....). The
reason for this, is that:
A: It makes common sense.
B: It is supported by witnesses.
C: It fits their apparent role.
D: It is supported by other documentation, some of which are governmental in nature.
Here's the skinny:
They are thought to be genetically engineered versions of their masters for the rigors of space travel.
1. Large cranial capacity: larger and more convoluted brain than homosapiens, thus, more intelligent.
2. Hard but flexible skeleton, more like cartilidge than bone, to handle impact. This goes along with the rubbery skin, again, more resistant to
3. One Heart/Lung organ which performs both functions.
4. No reproductive organs, they are cloned.
5. One liquid waste organ which acts as the entire digestive system (this is a large organ, and has parts similar to our intestines and bladder, but
are one distinct organ).
6. No hair (it is simply not needed, much as we will likely lose it all one day).
7. Large eyes (to deal with the unfiltered light of stars in space, when entering a solar system). It is also said to be quite bright on the
homeworld, but most "greys" have never seen it. These eyes are double-lidded for the same reasons.
8. Small nasal slits (as scent isn't that important of a sense to their mission profile).
9. Small ears, that are covered with a membrane, almost invisible on their outer skin, but there nonetheless. Communication is telepathic, so not
much use for these...
10. Small mouth, and no teeth, only a hard gumlike substance. They do not eat meat (nor could they chew most of it). That Strawberry Ice Cream
doesn't sound so ridiculous anymore does it? What would YOU eat with the same limitations? Most of their meals seem to consist of a vegetable paste
of some kind, which is synthesized on the ship. Their digestion is extremely efficient and results in little waste (when using this foodstuff).
11. Size is about 4 1/2 feet tall. Feet are more like a pad, though there are toe "bones" inside. Numbers of fingers vary, but most reports
suggest 6 (including the thumb) and sticky "pads" on the fingertips (like mini suction cups).
Hope that helps!