The game's collection data lists Inherited Mask as sold by a vendor NPC in Valdrakken.
Vendor
Zone
Map
Waypoint
Other items it sells
NPC #199599
Valdrakken
-
-
792
Vendor NPC, zone and position come from the client's collection source tables (CollectableSourceInfo and CollectableSourceVendorSparse); coordinates are the in-game map readout.
Build history
First seen in build 12.0.7.68887 (Midnight (patch 12.0.7)).
In the Appearances collection, Inherited Mask is listed as Quest. Appearance IDs: 80297, 80298. No other item uses this appearance, so it is unique to Inherited Mask.
Read from the World of Warcraft client build files.
Where Inherited Mask Comes From
Quests That Reward Inherited Mask
1 quest lists Inherited Mask among its rewards in Blizzard's quest data.
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Inherited Mask Compares
Who It Suits
Leather is the armor type Demon Hunter, Druid, Monk and Rogue wear. With Agility or Intellect, Inherited Mask suits Assassination, Outlaw and Subtlety Rogue; Brewmaster, Mistweaver and Windwalker Monk; Balance, Feral, Guardian and Restoration Druid; Havoc, Vengeance and Devourer Demon Hunter.
Transmog Sets
Inherited Mask is part of the transmog set Inherited Gear (Rogue, Monk, Druid and Demon Hunter only). The other 8 pieces:
Blizzard numbers items as they are created, so the named items next to ID 204592 (204587 to 204597) were usually added in the same batch as Inherited Mask: the same quest line, zone, vendor or reward set.