From Ardrana

Gruumsh, leader of the gods of the orcs, is a god of war who loves fighting for its own sake. He revels in strife and pain, pushing his people to expand their territories by driving other races from prime-material lands. The orcs have developed the ability to survive anywhere, even in the most hostile environments, simply because they need to. Of course, if they can strike at beautiful, serene land, they’ll do so – but because of Gruumsh, they’ll likely raze the place and return to the austere beauty of their homes.

Gruumsh is a harsh ruler; he constantly demands the most from his people, weeding out the weak and sending horrifying omens to those who don’t live up to his expectations. If a batch of berks just can’t push themselves to excel, Gruumsh usually destroys them by fire or the aggression of rival orc clans.

Note: Gruumsh originally appeared in this form in On Hallowed Ground for the AD&D game from TSR. His use here is for the purposes of providing context for the campaign only.