Use Taliis(==the best dbc -editor atm) with the config I wrote for CreatureDisplayInfo.dbc, and then replace the model of the mount you have with the protodragon(it's a number but Taliis will display you the name :O) and then change the textures(ie DeathKnightMount1Blue to ProtoDragon_NorthendRed ) and put the textures in the folder of the mount you have. Then it should work(not tested -->to lazy, and no wow-acc xP)