From here, he could get a better look at the huge paintings that covered the cavern walls. Directly above the entrance behind him, daubings of orcs and goblins cavorted atop a pile of dead - or at least very miserable - dwarfs and humans. To his right, an enormous black wolf reared up many times the size of the painted greenskins, frightened-looking goblins fleeing across the cavern wall from its snapping jaws. To the left, a similar rabble of lantern-jawed orcs retreated from columns of men, dwarfs, and what looked like children's drawings of skeletons, leaving the goblins cowering in holes beneath the earth.

At the very back of the cavern was the largest painting of all - a huge, goblin-faced crescent moon, a jagged crack splitting the crescent like a toothy grin. The black wolf rose up beneath it, jaws agape - but where it tried to bite the moon, its fangs had broken. Beneath it, countless painted goblins raised their stick-figure arms as if to cheer. The flickering light from the fires made the whole tableaux seem to shift and dance, casting long shadows over the uneven walls.
From the TavernKeeper thread, the description of the goblin history of beating Nahorek. I'm not sure we should read too much into this, seems equally feasible that the goblins are just attributing Nahorek's defeat by the humans to the Bad Moon but worth bearing in mind in case they actually did achieve something.