The Renewed Magmammoth is a mount that can be easily earned with Dreamsurges, Patch 10.1.7’s newest open-world content.
Waking Dream Portals
Every half-hour, Waking Dream Portals open up in whichever zone is affected by Dreamsurges. During this time, you need to fend off attacks from Druids of the Flame until a Flame Lieutenant is summoned. Defeating the Lieutenant drops several rewards including 1-3 Charred Elemental Remains.