Alien castes ?

[Local Trouble]

I tend to think that every soldier alien serves the role of "drone/warrior/praetorian" and all have the ability to reproduce.  Perhaps they can only do so once, which could explain why Brett's corpse was morphing into an egg and Dallas was intentionally kept alive to serve as a host.

[Corporal Hicks]

I think the easy explanation is eggmorphing occurs to generate a Praetorian/Royal Facehugger, when there's no Queen.

Yeah, that's been my fanon for a while too.

[Xenomrph]

which could explain why Brett's corpse was morphing into an egg and Dallas was intentionally kept alive to serve as a host.

There are those on this forum who would vehemently argue that Dallas was also being turned into an egg.

(I happen to agree with your assessment)

[Doctor Ash]

 Ridley may have have changed his mind later but the original concept was both, Dallas and Brett, were turning into eggs.

[Xenomrph]

Ridley may have have changed his mind later but the original concept was both, Dallas and Brett, were turning into eggs.

Well yeah and the original concept for the Alien was that it was going to be translucent, but that's not what ended up on screen.

[SiL]

Dallas' cocoon is clearly going egg-shaped, so it's not like the idea wasn't filmed.

[Xenomrph]

That's not the impression I got from Dallas' cocoon, I figured that was just what some Alien cocoons looked like. In my head it made more sense for Dallas to be the host for Brett's egg, but hey Aliens do weird shit and the original idea was that all the eggs on the Derelict were the eggmorphed crew, so who knows?

[SiL]

He's sitting curled in a ball, the cocoon is bowl-shaped, and it's starting to grow petals.

[Russ840]

So perhaps the first Xeno of any new event is like Big Chap and in the absence of certain Pheromones, let's say, that indicates a Queen or existing Hive in place, creates a royal egg via eggmorphing.

Then becomes subordinate to the future queen and no longer needs to Egg morph.

Perhaps you could say that in initiating the egg morphing, drone that does this actually sacrifices its self and begins to die due to the effects of creating and egg. This could be a nice nod to the idea that Big Chap was said to be deteriorating in some earlier scripts/drafts.

[Local Trouble]

As evidenced in Aliens, the entire scene was apparently retconned out of Ripley's memory and she defined "cocooned" as merely being used as hosts for the eggs.

[Xenomrph]

He's sitting curled in a ball, the cocoon is bowl-shaped, and it's starting to grow petals.

To each their own, and I don't know that it matters much either way. Within the context of 'Alien' it makes sense that he's turning into an egg, especially given the implied fate of the Space Jockey crew. Within the context of 'Aliens', I think it makes more sense that he's going to be the host for Brett's (presumed) Queen-facehugger.

[SM]

He's sitting curled in a ball, the cocoon is bowl-shaped, and it's starting to grow petals.

Quite.

If Dallas was supposed to be a host, Ripley could've broken him out same as how she did with Newt.

[Local Trouble]

What if Dallas was too injured?  Just because he was kept alive doesn't mean he was treated gently.  The alien may have broken his limbs during a struggle, leaving him essentially helpless and in excruciating pain.

Kinda like how they treated their victims in Labyrinth.

[SM]

He wasn't too injured though - just too far gone in the egg morphing process that he preferred death.

[Local Trouble]

I was responding to this:

If Dallas was supposed to be a host, Ripley could've broken him out same as how she did with Newt.