Gork and Mork

Gork and Mork are the twin Gods of the Greenskin race, each one representing two of the most defining characteristics of the Orcs and Goblins. Similar to the other sentient races of the Warhammer World, the Greenskins seems to believe and have created a different pairing of Gods that usually embodies that races baser instincts and emotions. As these emotions begins to manifest within the Realm of Chaos, they form into twin deities which nearly every Greenskin would instantly recognized as Gork and Mork. These two Gods of War embodies that species cunning and brutality. In the Greenskins use of words, Gork is brutally cunning, while Mork is cunningly brutal.

To put it simply, Gork is the embodiment of brutality and close-quarters combat, whilst his twin Mork embodies cunning and the use of unconventional tactics of warfare. As these distinctions can readily be seen between the Orcs and Goblins, it is very common for Orcs to worships Gork's brutality over Mork's cunning, just as much as Goblins prefer Mork's cunning over Gork's brutality. Usually however, most Greenskins can never understand the difference, and at times consider the twin Gods as one of the same. Nevertheless, these twin Gods of War are always readily worshiped by all Greenskins in almost equal measure, with many Shamans having the ability to interpret the Twins wishes and demands. Often these messages are ones of war, with many Tribes following the Shamans instructions of going to a particular location where other tribes shall gather and form into another Waaagh!

Twin Deities

 * Gork - is the primary deity of clobbering, smashing, breaking, killing and pummeling the rest of the world into submission. This is a notion that resonates strongly with the more warlike and highly volatile Orc sub-species, where their single-mindedness for violence and brutality often out-shadows their otherwise low cunning.
 * Mork - is the patron deity of cunning and shamans. Whereas Gork is most likely to clobber an enemy god in the face, Mork will happily wait until his enemy's back is turned before raising his club and belting him around the back of the head. It is Mork who is revered by the stranger and arguably more intelligent strains of Greenskins, the most prominent of which are the Goblins and Night Goblins.

Source

 * Warhammer Armies: Orcs and Goblins (8th Edition) -- pg. 35, 72