This mount costs 25 Platinum.
You can purchase it directly from the Rift Store Mount section.
Requires Level 25
Can also be purchased from ‘Nell Hara’ in Sanctum at /setwaypoint 7595 3029 (Guardians)
The ‘Steady’ version does not Autoscale, this can be useful in some situations.
You can also purchase an account wide unlock of this mount called ‘Escalating White Valmera Collar’ from the Rift Store.
This mount costs 720 Credits for patron or 800 Credits for non-patron.