Kill 8 shardwurms at DaggerFlow Glacier (disco xp) at ( 120, -250, -94 ) Copy/waypoint 120, -250, -94.
Head through Tizmak caves to other side then take ramp up at ( -54, -340, -368 ) Copy/waypoint -53.55, -339.72, -367.74.
Tizmak are non-agro and other mobs don't see thru invis. An Ancient Shardwurm is Level 90 ^ and packs quite a punch.
There are easier Shardwurm a little farther over on the inlet at ( -180, -286, 199 ) Copy/waypoint -180.22, -285.99, 199.12 and are a mix of 90 and 90v (paired), a young shardwurm also count as an update.
Rub your pet griffawn's coat with the shardwurm scales (hail your griffawn).
Note: The younger ones that are in pairs count as TWO instead of one, and are about the same difficulty to kill as one larger one. Might as well just kill 4 sets of the two younger ones.