"'He looks more than half like a goblin.'"
Among the Dunlendings who came to Saruman's banner of the White Hand in Isengard, there were large men, lynx-eyed and evil, who were called half-orcs. Many were counted among the strongest servants of Saruman. The half-orcs mostly perished at Battle of the Hornburg, either before the fortress walls or by the Huorns. Yet some lived beyond that day of doom and followed Saruman into exile, even to the Hobbit lands of the Shire, where they served the fallen Wizard until his last breath.[source?]
The true nature of the half-orcs is unknown. Perhaps they were Men whose blood, by the sorcery of Saruman, had become mixed with that of Orcs.