Like the Hellknight, I really like the design of the imp in Doom 3 a lot, so making this felt a little redundant. I gave this bad boy more Hellknight-esque mouth with the bare gums, so they seem like a distant relatives or something.
This design instantly got me to thinking about the Clone Soldiers from Serious Sam 3: BFE. A lot of classic baddies got interesting redesigns to make them look even more intimidating! (Though, admittedly, the Clone Soldiers were completely new to the game, though they functioned largely like the Zorgs from The Second Encounter and the Orcs from 2.)