Great Thunder Dragon Turtle
This is an unused look. This appearance has never been available on a player mount.
Notes:This colour of the dragon turtle only appeared later in the Mists of Pandaria. As such, it remains the only colour not available on a mount.
Note that each 'Great' dragon turtle colour uses a different saddle colour (unlike the basic mounts which all share the same saddle). In the case of this colour, we just picked the "silver" saddle for the image depicted here.