It is the earthly part of a human's soul, and you greatly resemble one. Are you sure you are not dead, and perhaps become lost on your nightly journey?

[By his deadpan tone, it might be hard to tell if Imhotep is serious, or just trying to pull his leg. He does assume that any messengers from the gods would have recognized him on sight, though, so it truly did leave precious few other explanations for why a man was walking around with bird wings.

That 'fated to transform' part was ominous, though...]

Hmph. I will not be made a vessel so easily. Tell me, what does the moon have to do with this?