Deep deep deep in a hidden subspace accessible only through a guarded demonic plane a vast form shifts and moves. It is blind and the bulk of it fills most of the darkness, stretching out in all directions.
Small wiggling "seeds" collect inside a drop of shining liquid at the very end of it, and are carefully collected and carried away.
It seems to be unaware of the process, endlessly devouring whatever is placed into its vast impossible maw.
Insects, plants, stones, artifacts, glowing crystals, all is fed to the great form. But with every meal there is a crucial ingredient.
A human, still alive. For without that, the end result would be worthless.