The Black Orcs or Morannon-Orcs are a breed of greater Orcs different from the even larger and stronger Uruk-Hai.
Their origin is unknown but they may be identical with the Warrior-Breed or Fighting-Orcs, the Hobgoblins or the larger Orc-Race from Barad-Dûr who fought in the second Age on the Gladden fields.
The Morannon-Orcs could also be identified with the Uruk-lesser-Orc halfbreeds known as "Gusmuras" in MERP.
The Morannon Orcs appear in the Movie Trilogy, The Lord of the Rings Strategy Battle Game and The war of the ring, The Battle for Middle-Earth Series, The Lord of the Rings: Conquest and Tactics and The Lord of the Rings: The Return of the King.Morannon-Orc like breeds also appear in LOTRO.
Morannon-Orcs from the Movie Trilogy
Aarlok Argdush Bolingúl Gartor Gashdrak Gordmúl Grarbag Guritz Murgash Gothmog
Note:In some other sources the above mentioned Orcs are considered to belong to different breeds, some of them lesser Orcs others Uruk-Hai and Orc Trackers