So I've been reading the Malleus Monstrorum, essentially the giant collected "monster manual" for the Call of Cthulhu RPG, and it got me thinking...
I've been reading Lovecraft since I was about 14 and have devoured every pastiche, homage, and satire I can get my hands on related to the "mythos," and I have to say, the way most creators handle Lovecraft's "deities," the Outer Gods and Great Old Ones.....reeeeeaaally bugs me.
My perspective on Lovecraft's cosmology has always been very firmly grounded in the "science fictional" aspects, as elucidated in stories like At the Mountains of Madness or The Shadow Out of Time. I have always interpreted the supposed "magic" and mysticism, the "occult" elements of the mythos, as a veneer of limited human perception projected onto alien physics, geometry, and biology--or at best, a crude attempt to codify and manipulate those factors to human advantage.
If there is any sort of underlying existential or metaphysical philosophy to Lovecraft's fiction, it's that the universe is vast, unknowable, at best uncaring, at worst hostile to us fragile, pitiful little monkeys. There are monsters out there--in outer space, in the cracks between space and time and the dimensions we can't perceive. "Mundane" or "terrene" life emerges from temporary, self-organizing little whirlpools of counter-entropy in a universe governed by randomness and chaos. The "gods" of the mythos are the quasi-physical embodiment of this chaos, and their interaction with us is generally along the lines of our "interaction" with bugs crushed thoughtlessly underfoot.
So here's my take on the life cycle of the Outer Gods, what I see as the "primary" emergent entities/organisms of the Lovecraft cosmology. No genealogies or family trees, no elemental water/fire deities, no warring pantheons of Elder Gods versus hoary Old Ones...Just the life cycle of a mindless trans-spatial organism, often exploitative and parasitic, writhing and squirming at the center of the universe.
It also occurred to me that the faux "pelagic" and "planktonic" qualities of the Outer Gods in their various life cycle phases could account for the aquatic quality of many mythos organisms--water, as a medium, is similar to space.