Revenant

Revenants are minor elemental creatures who once served as foot soldiers for the malefic Old Gods when the world was young. When the titans defeated the Old Gods and chained them beneath the cold earth, the wicked revenants and their greater elemental cousins were banished to the Elemental Plane. Locked away from the world they once ruled, the fire of the elementals' hatred for the titans and their creations burned with increasing intensity. As the millennia passed, reckless mortal wizards began to summon elementals back into the physical world. Free at last, many revenants struck out against the mortals that had summoned them and set out to forge their own destiny among their native elements in the world. These evil beings exist only to inflict strife and sow elemental chaos. Though they have limited intelligence, their sheer hatred and will to destroy make them fearful opponents when encountered in the wilds of the world. Many still live on the Elemental Plane.

Revenants are hateful undead creatures who are outside the domain of Ner’zhul’s control. Bonded to base elemental spirits, these phantom creatures live only to rage and use their powers for destruction.

Revenants appear as undead elemental creatures with the ability to cast elemental magics according to their type. Although appearing undead, Revenants have no affiliation with the Scourge as they have some sort of innate immunity to Ner'Zhul's psychic control over undead. They remain neutral in the conflict between the Horde and Alliance. They look similar to floating suits of armor, bound by elemental energy, according to their elemental type. They also wield large maces and carry giant shields. The most famous revenant is The Guardian, protector of Frostmourne.

Wrath of the Lich King
With the new expansion, Wrath of the Lich King, revenants appear in several different zones of Northrend, such as the Dragonblight and Zul'Drak. They now have a less refined appearance, with cruder-looking armor made of their element in the stead of the ornate armors of Warcraft III. They also do not seem to be undead at all.

Subraces

 * Death revenant (Earth)
 * Earth revenant
 * Fire revenant
 * Frost revenant (Air, Cold)
 * Ice revenant (Cold, Water)
 * Lightning revenant
 * Water revenant

Warcraft III

 * Deathlord
 * Deeplord Revenant
 * Eldritch Deathlord
 * Revenant of Burning Souls
 * Revenant of the Seas
 * Revenant of the Depths
 * Revenant of the Tides
 * Sea Revenant

Trivia
The Warcraft III model for the revenant was originally for the Death knight.