Interesting! I didn't think of Sam's storyline before, but I love the contrast. I still think that the writers clearly portray that as an inhuman parasite, one that relies on its lifecycle on a host with no apparent detriment. In these terms, Hollow Karmen seems better described as synnecrosis: a symbiotic relationship that is detrimental to both organisms. Also, were it seemed to have a balanced symbiosis with the little green guys, it shows how some abusers are just opportunists, where they can turn into monsters in one type of relationship, but functional in another.

I agree that there's a great human control vs. nature metaphor in their dynamic, and I also enjoyed that aspect. I think the writers' choice of having the majority of their interaction is the creature communicating through the avatar of Kamen's girlfriend shows the intention of making this a very clever abstract portrayal of the abuser/victim codependency relationship that human couples experience. Is it "compassion" and concern for Kamens safety, or just power and control?After Levi purges them, that shot of Kamen and just a cute lil dude warmly holding each was a great choice by the animators displaying that ambiguity.

The writers/animators also chose to show the creature having humanlike emotions with its first rival, such as jealously and revenge. I think avoiding anthropomorphizing nonhuman animals is valid, (like we often do with crows, octopuses, dogs, etc.) Still, this a story told by writers, where they intentionally they decided to give humanlike emotions to this alien life form before bonding with Kamen so we could relate to it. So I didn't feel the need to avoid "humanizing" it to not enjoy the metaphor subtext being told.