The game's collection data lists Yaungolian Helm as sold by 2 vendor NPCs in Orgrimmar and Ironforge. The first vendor stands at 57.1, 89.9 on the Orgrimmar map.
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 5.5.4.69585 (Mists of Pandaria).
In the Appearances collection, Yaungolian Helm is listed as World Drop. Appearance ID: 17768. 14 other items wear the same appearance; 10 of them are listed here.
Read from the World of Warcraft client build files.
How Yaungolian Helm Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Yaungolian Helm suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Yaungolian Helm is part of the transmog set Swarmbreaker's Battleplate (Warrior, Paladin and Death Knight only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 93097 (93092 to 93102) were usually added in the same batch as Yaungolian Helm: the same quest line, zone, vendor or reward set.