Giant eagles usually stand 10 feet tall and have wing spans of up to 20 feet. They share the coloration and fighting methods of their smaller cousins, inflicting much more damage, of course.
Giant eagles build their nests only in high mountain passes, where they have room to fly undisturbed. They are far more social than wild eagles, and up to 20 have been discovered nesting in the same area.
Note: Giant eagles originally appeared in this form in the 2nd Edition Monstrous Manual for the AD&D game from TSR. Their use here is for the purposes of providing context for the campaign only.