Unhallowed Champion

Unhallowed Champions are Unique Brood Daughters found in the Unhallowed Essence Set Dungeon in Diablo III.

In combat, they have an Illusionist affix, but their web shots will deal very significant damage if they hit. The illusions do count towards the requirement to hit 20 enemies with a single.

Development
On PTR, they had a title listing them being resistant to every Elemental Damage type.