I apologize for the vagueness of this request!
The creature I'm half-recalling was probably created a decade or more ago and I only remember it from a single issue (but of what series, alas, I don't recall).
It had grayish stone-like skin and wore a shemagh-like scarf around its face from about the nose down, and possibly some other clothing. Mid-fight, Batman pulled off or loosened this article expecting to see some human features but he instead revealed a very demonic mouth which startled him (and I think the reveal frame was very large, perhaps most of a page, if not an entire one).
I am almost entirely convinced it was not Etrigan or a different incarnation of him. It was vaguely bat-like, its head somewhat resembling the Tengu mask Batman once wore). Instead of those ears, I seem to rememeber protrusions on either side of its head shaped like wide axeheads, as though it was related to a double bit axe or something.
I remember being spooked by the reveal of the critter's face but darned if I can recall its specifics. I don't remember if there was a nose at all, or if the mouth was super-toothy or gruesome or what—only that it was definitely not human and quite menacing. As to the rest of its body: I think it was about the same size as Batman, but more lanky/sinewy. I don't think it was winged but am not certain.
Complicating matters, I think Batman consulted Jason Blood briefly in the issue because he suspected the creature he was after to be supernatural/demonic. I don't think Etrigan himself featured. I also kinda-recall that the creature was assassin-like or had been summoned to kill people and/or protect somebody. I think it was killed or somehow died by the end of the comic. I am not at all sure about the stuff in this paragraph.
Gah! It's going to haunt me. Maybe I dreamt it all.
Thanks for any help you can provide.