Ancestral War Bear

Coming in Patch 12.0.1.

Its tread resounds with the memory of ancient warriors, a living symbol of the unwavering ferocity the Amani revere.

Riding Requirements:

Level 10
Apprentice Riding

Source:

Looted from Honored Warrior's Cache in Solemn Valley, Zul'Aman (Midnight).

Notes:

This mount can be looted from the Honored Warrior's Cache, found in a cavern under a tree - entrance at 47.0, 82.3 in Solemn Valley below the mountain west of Temple of Akil'zon in Zul'Aman (Midnight).

First, you should visit and interact with the cache, but you won't be able to open it yet. Now you need to kill and loot four Echoes of the Past around the zone. You summon them by clicking on Honored Warrior's Urns at specific locations:

Nalorakk's Chosen - found at 32.7, 83.5 - on a rocky outcropping between waterfalls just east of Nalorakk's Prowl. Drops a Bear Tooth.
Akil'zon's Chosen - found at 51.6, 84.9 - on a ridge half way down the mountainside south of the Temple of Akil'zon. Drops an Eagle Feather.
Jan'alai's Chosen - found at 54.8, 22.4 - just south of the Temple of Jan'alai. Drops a Dragonhawk Feather.
Halazzi's Chosen - found at 34.5, 33.5 - above a lynx den, east of Temple of Halazzi. Drops a Lynx Claw.

These are level 90 NPCs and will be more difficult at lower levels.

With the four looted items in hand, return to the Honored Warrior's Cache and you should be able to loot the mount.