The area near Sleepers is probably the best place to focus. I spent 10+ hours before I got my first egg.
I started tracking the whole zone, but only had success when I concentrated on killing Mammoths around Sleepers and on the line to Kael.
loc -5914 +1650 is a spawn point for Elder Griffins. The placeholder can be a wolf. Respawn is very fast. Less than 5 minutes
Edited, May 26th 2019 6:13am by Discordia