Narg is an eight foot tall Trolloc that has a wolf's muzzle and goat hooves.
He is one of the Trollocs who attack the al'Thor farm. He hides in Rand and Tam's house pretending to be dead, waiting for someone to return. He then attempts to talk Rand into coming with him to see the Myrddraal. He attacks Rand and is impaled on Tam's sword.
Narg is also the only Trolloc that Wheel of Time readers have witnessed speaking in the common tongue, though quite crudely.