So I've been trying to do a little worldbuilding within the Alien universe, and one interesting idea I came across was the 'Red Xenomorphs' from the Aliens: Genocide novel ; While they were 'wiped out' so to speak, I had been thinking of how they could make a comeback and be an interesting addition as a canon 'breed' of Xenomorph, if only for fun scenarios or story-telling potential of planetwide Xenomorph battles and whatnot.
- For one, they seem to be a natural/recurring mutation amongst the Xenomorph XX121 strain; The RPG book mentions that Xenomorph Hives can start to experience 'genetic drift' as they get larger, which is undoubtedly a call-back to the Red Xenomorphs from the Genocide novel. The fact that this is noted to be an existing condition suggests that even if they had been eradicated, there's a chance they can/will come back.
- They're considered 'deviant' and display some unusual phenotypical characteristics; While the novel/comic differ in terms of appearance (novel suggests they're at most black w/ a red tint but the comics and other materials show them as being bright red) for the sake of ease and parity let's just say these guys really are that brilliant crimson red. Perhaps due to their 'mutant' status (they're described as producing unwanted 'mutant' Jelly) they could occupy a unique 'niche' within Xenomorph evolution or phenotypes
-The Red Xenomorphs could be a 'slave-maker' breed, like Polyergus ants; They're unable to procure or reproduce in the same manner of the mainstream phenotype, and thus raid rival hives for hosts, food, and to steal/enslave the Drones and Warriors to serve as the workers or the means with which for them to gather hosts. This could also work as one of their nicknames are 'The Changelings', and in folklore Changelings would whisk away children as soldiers or servants
- Their 'nests' could similarly be ephemeral, being more like Bivouacs/living fortresses of the Xenomorphs and resin (to a greater degree than the normal strain's even) than the more sessile, permanent structures of a towering xenomorph hive.
- The established caste system could thus be 'altered' slightly or otherwise changed to replicate their warlike nature and niche; Warriors and Queens would be built almost solely for combat, perhaps lacking the methods to reproduce in the 'normal' way (ie parthogenesis). Perhaps we could even introduce a true 'male' alien; Male Army Ants for example are free-living and burly bugs with large, sabre-like mandibles who fend for themselves and search for the pheromone trail of a receptive Queen, whereupon they have to prove their fitness and more or less run through a gauntlet of worker/soldier ants to get to the Queen;
- Similarly, many slave-maker ants operate in a similar manner, with Queens sending a call signal after a successful raid (this is also reminiscent of Praetorian development too, with the latter being noted to be driven from the hive only to return and have to 'prove their worth' by fighting their siblings). This could of course be justified by them being a mutant/divergent strain that occurs only in the largest Hives, much as 'King' Xenomorphs are said to; Or perhaps most fittingly the very red-tinted 'Rogue' Xenomorph could be 'naturalized' as a sort of 'Ravager' or 'Rogue Male' Xenomorph, a competitive and self-sufficient consort to the Red Queens. Of course, they wouldn't really be 'kings', a better name would be 'Ravager' or otherwise some name or play on Praetorian/Drone/Alate, but that's the concept I have thus far.
- As for how/why this bizarre strain could exist, it could be a sort of built in 'kill-switch' if we follow the idea that the Xenomorphs were developed as a biological weapon; When they get too big, a divergent strain occurs and they 'in-fight' until they wipe themselves out or otherwise can be 'cleaned up', especially considering the 'sterility' of the Red phenotype. Of course, as good ol' Goldblum says, 'life finds a way', with the Red strain being a recurring recessive mutation occuring in cases of genetic drift but also having evolved a 'workaround' their own physiological shortcomings.
TL:DR; Slave-Maker Ant + Driver Ants + Xenomorphs = Red Xenomorphs, please C&C