There are two races of orcs: the orcs of swamps and the orcs of mountain. The fists has green skin, they are fierce fighters, they hate humans that have chased them like animals. The seconds has an yellow skin and covered by few hairs, they are more resistent because of the strong skin and fierce fighters.
Also if their intelligence is less than an human their shamans are good wizards. Their clerics are tied to neutral or evil gods.