Sculk Variants for Mobs that Spawn Below Y:0

It doesn't make sense for regular mobs to spawn so far down in the world, so how about making sculk variations of them that exclusively spawn in the deep dark? They would basically be the regular overworld mobs, except they have a "sculkish" blue texture, and deal more damage. It would be cool to see sculk zombies, skeletons, and the other basic mobs. Endermen, however, would not have a sculk variant.