Okay, guys. I am by far and away, NOT a Warhammer fluff guru. But I enjoy the setting, and moreso, I'd like to run a Deathwatch game focusing on Hive Fleet Dagon, and more specifically, the stuff that I'm pretty sure is not explicitly mentioned anywhere. As such, I'm asking less for specific examples or mentions in the books or something, and more for ideas based on what we know.
What is the origin of the Tyranids? Why do they do nothing but consume, produce more Tyranids, and then keep consuming?
I know the basic answer to that is 'because that's what they do' and that's totally cool with me. But what if, there was something at the center of it all? As an example: Nids consume biomatter, which is used to produce more Nids. But what if they actually have a goal in mind? What if they're consuming biomatter to eventually give birth to… something else? A god, perhaps.
That's just a basic idea, but I'd love to hear stuff from fluff gurus or just any ideas in general.