: I think they're one of the younger races.
I would have to disagree. Obviously, according to the flavor and storyline, Forest Giants have been in conflict with the Trow for quite a while, possibly from the begining of time.
Prehaps they are opposing forces of nature, the abounding life of the forest vs. the cold lifeless existance of clay, stone, iron, etc.
Or prehaps in the begining, the Trow and the Forest Giants worked together as brothers, living together off of the Forest. However as the Trow broke away from Mother Nature, begining to cut down trees to build thier mighty cities, the horrified Forest Giants retreated farther into the Forest, and so the great hate between them began.
I believe that this does not disrupt the legend of them destroying every new race, as the Forest Giants were NOT a new race.