So news has come out and is probably going to hit Mmo-champ updates soon that when Hunters get their Class Mount through the quest, you will gain the ability to specifically tame "Flying Beasts" like Gryphons and possibly Hippogryphs (hopefully wyverns too).
A lot of color variations for Gryphons are not in the wild though, hope that changes. Spectral Gryphon! Hoping the high mountain eagles are included as well.