How to get the Bleakhoof Ruinstrider mount (World of Warcraft: Legion)

The Bleakhoof Ruinstrider got added to WoW in patch 7.3, and to get this mount you need to complete the achievement "...And Chew Mana Buns". This achievement can be completed by slaying a total of 2,000 non-trivial demons in the new patch 7.3 zones. Getting this will probably take a good while, but it is a nice reward to work towards while doing World Quests in the areas.