Mathogg

Mathogg was an orcish military leader who led an orcish encampment north of the Darkspear village shortly after the Third War.

The encampment was raided by the Kolkar centaur and its inhabitants were taken captive. He was found by Rexxar, Rokhan and Chen Stormstout, who agreed to help the captured orc. The trio of heroes hunted down and killed the Kolkar Khan Gragtor, taking from him the key needed to release Mathogg and his comrades. Upon release, Mathogg vowed that, now that his people were safe, he would travel to Orgrimmar to lend his services to the Horde.

Speculation
Similarly as Mogrin, Mathogg called Thrall his chieftain, indicating that he was from the Frostwolf clan.