David or Peter, one of them is our new Villain. Part 1

 a superb theory.  well thought out.

this could fit with the theory i have on the engineers.  the engineers are not the focal point of the story.  the well defined, pale blue ones are actually CREATED by the elders who created the ultimate designer baby if you like and made them purely with the purpose to seed the galaxy.

the engineers (pale blue, well defined) are not male or female, they have no sexual orientation, they have no need to reproduce. their job to seed the galaxy in the way we saw at the start of prometheus.  they break down using the goo looking like a sort of sacrifice.  this small faction of beings grew tired of giving their life in the order of creation and so a stand off / war of some kind broke out.

the beings in empire are maybe more human and were created in the same way as the start of prometheus.

the we came from them idea. the beings in empire did too

that sort of says weyland created david.  the elders created the engineers.

the engineer gives david a look before ripping off his head.  was this sympathy or empathy towards david for being a fellow creation.  before the act.

the engineers are created that size and this is why we think they are male but in fact neither.  the tubes in the cryo chamber are used to feed them during flight.

@ sherries, I like that too, so the ones in robes seen in the trailer or the deleted scene at the start of Prometheus are the ones who created the biomech style engineers? The Elders? Or are the elders yet to be shown so far?

yes. the elders created the engineers (well defined, pale blue ones )in order to have a being to seed the galaxy.  

fits with the creator / creation themes?

i was looking as to why the well defined ones looked younger / different.  maybe they were created that size and that is partly why they havent seemed to age / age slower - due to the quality of the process in which they were created.

the colour is maybe due to a creation process or lack of sun

I am also along those lines. My hunch is that David will himself eventually fall victim to his own creation in the most gruesome way... as the Space Jockey in the "derelict". By putting on the biomechanical suit he will be susceptible to becoming impregnated by a facehugger that's loose on the ship. However he does not know that. I also think the thousands of eggs in the derelicts belly are the occupants of the Covenant and Davids finale is that he will carry his deadly cargo to earth but then fail in the process.

That does make sense and fills in the roles of the 2 separate groups.  The question of why the 2 groups have conflict may even be answered in there. The elders used to have to deliver the cloned ones to a planet which considering the seeding process seems inefficient doesn't it? Maybe what determines the physical difference between them is that the seeders are designed really strong to provide a degree of protection against atrophy that damages bones and wipes out muscle in zero gravity. Combine that with the biomechanical suits that don't look like they're ever coming off, and your theory covers all the bases needed to be probable in my opinion.

Re: their color, if you're right about their purpose as seeders it also then would follow that most if not all of their lives are spent aboard ships, or underground with zero sunlight exposure. Either due to being in space, or on a moon like LV-223 which kills humanoids without suits to breathe in, time spent in the sun for either group is slim I bet.  =] 

@ Necronom 4, how do you mean the thousands of eggs are the occupants of the covenant?  The crew is rather small isn't it?

However, Im pretty sure david isn't at risk of becoming a host to an alien or attacked by a facehugger in general due to either his biology or (imo) being the one who designs the cycle of the alien from egg to end in a way that it requires humanoids to effectively function as their target. For example, the egg will only open to release the facehugger upon detecting the prey it was designed to kill (humans) being present.

Putting on the bio-suit which renders him a target is a great concept, the only problem is there is no need for him to use such a suit, and of course the size of the space jockey is much bigger than even the regular engineers. Explaining how david came to be that size would be difficult.

I do agree that David will have a very bad ending when the time comes. Both the other guys caught wreck when their time came. Ash got his head knocked off and set on fire, Bishop got impaled and torn in half, went into cryo-sleep and then crashed on a planet lol. David's in trouble and lucky he doesn't feel pain cause his death wont be pretty like you said.  

@Necronom 4

your idea of the 1000s of eggs being the covenant.

i think david plan is to infect the ground crew then go after the main ship.  hence, alien : awakening (from cryo).  so i do think the plan is to get at the 2000 colonists and that may involve impersonating walter.  

i think your right about davids interest in the colonists im just not sure exactly what that looks like yet

@Don we've only met the crew of the Covenant. But onboard are 2000 people in hibernation that are intended to make a successful colonisation on the destination planet they are travelling to (note not Paradise). 

Regarding him being in the suit, I'm not so sure since piloting the craft may require the pilot being strapped into the suit and what I call the penischair :) The pilot becomes "one" with the ship. Anyway, as to the size the suit can maybe make up for the size difference since looking at it in Prometheus when the blue guy enters the suit and chair, everything fuses together seamlessly. Really hope that they have a good explanation for the SJ and derelict if now these prequels will lead upto Alien directly. 

Otherwise I was thinking that maybe they could just leave the SJ and derelict still as an ancient mystery. Yes David will create the Xeno and all that, but someone has done it millions of years before. History repeating itself.

 the covenant is set 10yrs after prometheus so i think the covenant mission will of been in the final planning stages when prometheus embarked.   david will of had knowledge of this.  so he tricked them with a signal into a detour so he could get his plan into action.

@Necronom IV: 

Since seeing Prometheus, I've been thinking the same way about David. Although it would be much more in the spirit of Lovecraft to have the Space Jockey as some enigmatic, deep space being - I feel David 8 will in fact become the Space Jockey, after fusing to a bio suit (rendering him susceptible to a Face Hugger strike due to the living tissue)... and I always felt that he would suddenly bring the Prometheus myth to life... Trapped in that chair, forever having his chest torn open, day after day... at the mercy of repeated Face Hugger attacks. Due to the suits ability to "produce new cells" (assuming this was not a result of the black goo when they examined the engineer head), the wound would heal itself.

Over and over.

His immortality will ultimately be his downfall, a permanent incubator/alien birthing machine to the host of alien cargo in the hold beneath him.

Definitely some bizarre imagery here, and not fool proof (ie. I'm not sure about the fossilization process regarding the Jockey in Alien)... but perhaps fitting, especially if he was playing with the technology of the gods, and 'circulating' it among humans (yes, I'm referencing the embryos from Covenant - they may well be the eggs after David has corrupted them). 

sls - david the space jockey?

doesnt sound that much of a stretch.   that is a good theory im going to have a look at that myself.  seems as tho it could fit 

@sls, Yes I think this is a very plausible scenario how this will pan out. If David want to wipe out all of mankind, then he will want to use his brand new state of the art perfect organism/weapon xeno on mankind. Killing off the crew of the Covenant and the beings on Planet 4/Paradise will only serve as a test and a way for him to develop the weapon. He will most likely be very proud (like his creator Mr Weyland) upon having succeeded, and that will lead to his undoing and demise. 

Re the fossilisation, there is none. The suit and the pilot chair are one and the same and fuse together with the occupant. Hence to our misunderstanding it looks like "it's grown out of the chair" as per cpt Dallas remarks.