A variety of different types of Champions were added in D2X. They receive various bonuses to make them tougher than standard monsters of their type. Most champion monsters spawn in bright colors, making them stand out from standard monsters. Ghostly champions are translucent, and are the only type of Hell Bovine that look any different from all the rest.
Note: This modifier will set the physical resistance to 80% not increase it by 80%. You may found a “Immune to Physical” ghostly monster but it in fact only has 80% resistance and the description is wrong.