From WoWWiki

Little is known of the Draenor giants, other than the fact that they lived on the world of Draenor. They also had two eyes, and its skeleton is human-like but very big. They are most likely extinct, either from the destruction of Draenor, or other factors.

In Warcraft 2, the Temple of the Damned structure was said to be constructed from the bones of these giants.

The Horde Player's Guide says that the ogres are one of the last races of Draenor's giants, implying that there has been more than one race of giants that have lived on Draenor.^{HPG 156}

These creatures may very well be related to the Gronn, the lords of the ogre race....and perhaps all races of Draenor's giants may be related distantly.