Dude at the start of the US trailer. . .

the SJ king when they first visited Earth.......

An Engineer or Human tranforming...into what, wish I knew.

sorry but this has to be said, IMO it HAS to be the thing that eventually becomes the Xeno that Cocoon's Dallas and reeks Havoc on the crew of the Nostromo...or...it's immediate predecessor!

Can't see it Sparty From the cave paintings and artefacts - humans appear to me to be worshipping some sort of giant aka the 'giant blue Engineer'. IMO from Shaw saying "there was a king, he ruled, and then he died" is either an Engineer that ruled us and gave us a gift of evolution; thus the first few humans have the 'blue viens' as they are artificially changed to aid their evolution; mainly to be slaves. The 'progenitor' to me has to be the 'white worm' that is either on the planet the Prometheus goes to by: 1. coincidence or 2. is a biloogical weapon 3. lives in harmony with the Engineer to give them longer life or super strenght 4i. is an infant Engineer What ever it is the 'progenitor' is created with Shaw and Holloway getting jiggy whilst he has been infected with something...........

I was wondering about that guy as well. A primitive human being genetically manipulated? A benevolent alien being acclimatized to earth to "rule" to drag humans out of caves and to teach them? The saucer shaped (spacecraft?), obviously not the same as the derelict type of spacecraft seen before. Another race involved? The same image scattered around from ancient civilizations may not mean an "invite" but a warning not to go to there? She does state that "we were wrong"... Yeah, pulling at straws but can't help it....waiting 32 years for an answer for who the SJ was...(how my sisters got away sneaking me in the cinema being 11 years old is beyond me....)