I dig fantasy like this that really pokes at real-life dilemmas, like the finite nature of, say, buildings or your work or your namesake.
It's fun to think about what the snake could be. It's a little too late for me to come up with something super profound, but it could be death (which is odd, since no one really got killed. But! Death is the ultimate changer-of-shapers. Like, death changes the form of things, like the snake does to the building) or time (which explains the hourglass and why the snake was made into it. Time brings death and change and all that neat stuff.)
Too many parentheticals?
Never!