Archvile was without a question the most badass of all the monsters in Doom 2. To me, they are one of the finest examples of enemy-design, not because of their looks, but because they actually changed the entire flow of combat. Not only can they set you on fire with their will alone (which forced you to stay ot of their line of sight) but they also resurrected the enemies you spent so much time, affection and bullets to slay. This put them on top of the target-hierarchy. It was crucial to wipe these bastards out at any cost as soon as possible. That's some top-notch enemy design.
I went for a different look altogether. I wanted this guy to have sort of a clergyman-thing going on, so I made his skull resemple a pope's or a bishop's hat. I also added a huge skirt made from human-flesh, to create a sense of some type of disturbing fetishistic insight, so that he's not just a beast, but a sentient and self-aware entity. This also gave him a more distinguishable silhouette from rest of the humanoid beings.