Orcs are the simplest and most fundamental tool that evil gods and demons have to wreak their machinizations upon the World We Know. They enter the World We Know through the waters of brackish fens, dark pools under moonlight, or the sea. They can be found in the Shadow Realm as well, awaiting direction from their masters.
While goblins have pebbled skin which is often bright, striped and be-spiked like a lizzard, orcs are mottled, dark and smooth like an eel.
While goblins are maniacal inventors, orcs are patient builders, constructing monoliths and monuments.
While goblins often sing, orcs do not, though on moonless nights a low inhuman chanting may be heard coming from Orchenges.
Orcs are dutiful in the work they do for their masters, however, this work is merely vocational. The gods that orcs truly worship are much, much older and long since vanished from any world known to orcs or men.
Orcs are fascinated by human women.