Target your gryphon pet and activate the bone. (You must be in the Great Divide zone to activate the bone!)
Your gryphon will disappear and you will get a quest update.
Find your pet by checking your map for a small blue area. On TLE blue highlights are disabled, see the crafters tip below for locations
Click the gryphon to auto-update and auto-finish.
If you do this as the last step on the questline, you will need to use the Summon Gryphon item in your bag to open the option to choose the style of gryphon you want.
Crafters With Lower Adventure Level[]
For crafters your pet griffon will be at one of the following locations:
On Snowfang Isle in the Icy Fingers at the gnoll camp.
If your crafter is not near level 90 adventure: A safe path is to enter the water at ( -1198, -542, -2046 ) Copy/waypoint -1198.22, -541.69, -2045.84 (watch out for Iceclad Sleeper Sharks) then swim up to the ice at ( -1110, -544, -1923 ) Copy/waypoint -1109.66, -543.63, -1923.08 dive and swim under the ice. WATCH FOR SHARKS!! You can make it without water breathing, but it’s nice to have a totem of the Otter handy. Once clear of the ice, surface and swim to a ladder at ( -911, -544, -2192 ) Copy/waypoint -910.54, -543.73, -2191.91. This is the same area where Ruffin is at. Griffon is typically just past Ruffin. I would recommend going back down the ladder instead of jumping off the side to do the return swim. I tried that and met a shark upon landing. Quick way back!
An even easier method is to hop on the griffon from the Othmir camp, and fly toward Thurgadin Docks. The griffon will fly right over the top of the Gnoll camp, allowing you to jump off.
On Blisterrock Ridge, not far from the Ring War griffon tower, at ( -40, -370, -672 ) Copy/waypoint -40, -370, -672.
Between the Remnant of Ring War and Goahmari Village, at ( 358, 16, -46 ) Copy/waypoint 358, 16, -46.
On the hill over the Storm Gorge Staging Camp (mission questgiver cave) ( 523, -332, 837 ) Copy/waypoint 523, -332, 837.