Random.
... I dreamed of an undead creature - the blood of a victim of some vile and lethal process. It can speak, but it's otherwise inert, and it ceases to be when it all dries up. However, that takes longer than normal and it can be mixed with dirt to produce a viable minion. I don't know how much of that came from the dream and how much I tacked on when I was conscious. Eh.