The following guide explains How to Farm the Dune Scavenger Mount from World of Warcraft: Battle for Azeroth. This beige hyena is a random drop off Sethrak and Faithless NPCs that inhabit the Vol’dun zone of Zandalar. This mount is a zone-wide drop and doesn’t have a specific NPC source.
Currently, the best way of farming the mount is to kill the Faithless NPCs.
This is a bind-on-use mount so you do have the option of selling it. It’s currently selling for 200 to 300k at the Auction House. Note that at the time of writing this guide, Battle for Azeroth is live since 2-3 weeks. Its value will of course slowly drop in the coming months. Don’t wait until it’s too late.