Unnamed invisible enemy (Hacx)

????? are enemies from HacX.

This foe only appears a couple of times in the game, on Map10. It is completely invisible and has the same ranged attack as the Thorn Thing.

The editing document included with the game makes no mention of this foe and states that the Doom object it replaces (the Revenant) is unused, suggesting that it's inclusion in the game was probably a mistake.