The cuddler is a strain of sentinel with pheromones powerful enough to affect humans, it has three to choose from: pain relieving, mood stabilizing, and sleep inducing. None of them affect other xenos, as they can't feel pain, don't have moods, nor does putting them to sleep mid fight help anyone, instead all three of these affect humans when rested on, especially while they are nested.

Pain relieving would be equivalent to paracetemol in strength, don't want to stress out the new born with an agitated host, mood stabilizing reduces aggressive tendencies and functions like an ssri, helping to treat depression and fear in the host (which to be fair is probably common considering xenomorphs), and sleep inducing relaxes the muscles and makes those who have fallen asleep to paincrit stay asleep longer.

Yes this is a meme, no it's not borderline erp, and also no i dont think this will ever be added, but god damn i think its funny comparing sentinels to professional cuddlers but with actual pheromones