night-stalker

A person who is habitually abroad at night, especially in order to conduct illegal business.

[S]he accordingly proceeded with unrelaxed rapidity, startling the deer who came out into the open plots to browze, or scaring their lurking enemy the night-stalker, who, with his toils and engines, concealed himself in the adjoining bushes, that he might ensnare and carry off the fattest of the herd.

“You can't conceive what he fancies. It seems, according to his account, that you are a night-stalker.”

A monster or other malevolent figure that moves about at night; a shadow-stalker.

“Thou wilt have no need to bury me, for if I get my death he will have eaten me all dashed with blood, he will bear away my gory corpse, he will taste me; the night-stalker will devour me without mercy.”