Caustic Venomfang

Sold by the Skull of Er'inye, the Corrosive Coin vendor beside the Altar of Corrosion at the Amani Foothold in the Vaults of Atal'Utek, for 10,000 Corrosive Coins. The Vaults are the underground temple inside the mountain of The Coiled Isle, added in patch 12.1, and the coins are earned there: from the Vaults' public events, daily quests, enemies and treasures.

Time there about 2 min a visit

Guides Wowhead: The Vaults of Atal'Utek Patch 12.1 Zone Guide - Activities, Rewards, and Player Power · Method: How to Farm Corrosive Coins in WoW Midnight · Method: Skull of Er'inye (Corrosive Coins) Vendor Location and Rewards

• The Coiled Isle opened: The Curse of Ula'tek campaign as far as What Lies Beyond the Fog, which leads to the isle and the Vaults · about 3 h
• The vendor opened: Into the Vaults of Atal'Utek, the introduction quest from Warleader Abdumati or Mok'sa the Stone inside the Vaults. Done on one character, it holds for the whole warband · about 0.5 h
• 10,000 Corrosive Coins, a warband currency earned only in the Vaults and on the isle: 20 for a Temple Patrol (three are up every 10 minutes), 75 for a Temple Strike, 175 for a Temple Incursion, 200 for the Ancient Foe after it, and more from daily quests, enemies and treasures · about 10 h

In all: about 13.5 h of play, starting from nothing.

/way is for the TomTom addon. Travel times are estimates: flying at 55 yards a second in a straight line and 30 seconds for a portal. A star marks a portal that needs a quest or other unlock done first.

The Skull of Er'inye sells it for 10,000 Corrosive Coins. The journal's cost of 10,000 names no currency; Wowhead's vendor data for the item has the Skull of Er'inye (npc 272751, "Venomous Goods") at 10,000 of currency 3448, Corrosive Coin, and a 2026 Wowhead comment and two Method guides say the same. The wiki's page for the mount (edited 2026, before the patch) leaves the price blank, and the wiki has no page for the vendor or for Er'inye. Added in patch 12.1.0 (11 August 2026); a flying mount; the item binds when picked up (wiki, Wowhead's tooltip).

The vendor, on the Vaults' own map: 51.2, 62.4 by the Wowhead comment (/way #2509); Method has 51.13, 62.37 and 51.3, 62.4. Flying is off inside the Vaults; the tunnels in give ground mounts a burst of speed (Wowhead's guide). The three gates on The Coiled Isle (Wowhead's guide, wiki; which is nearest to the Amani Foothold was not checked):

• Gate of the Western Fang 31.8, 64.9
• Gate of the Serpent's Eye 43.4, 44.2
• Gate of the Eastern Fang 45.4, 64.9

The vendor's unlock rests on one source. Method's vendor guide, written the day before the patch, says the Skull sells only after a short quest from Warleader Abdumati, done on one character for all, and gives quest 98388 under its test-realm name, Certain Doom. Wowhead's tooltip for 98388 now reads Into the Vaults of Atal'Utek, the Vaults' introduction, which is already counted for the other Vaults mounts. Wowhead's guide mentions no unlock for the vendor.

Coins: Wowhead's guide (updated 2026) calls them a warbound currency, looted from enemies and treasures and given for Temple Assault events and daily quests, and says that killing serpents in The Underbelly should gather them quickly. What the events pay: Neither guide gives a rate per hour, a weekly limit or what the daily quests pay, so the ten hours are an estimate made here and the weak figure.

• a Temple Patrol: 20, with three up every 10 minutes (Wowhead's guide)
• a Temple Strike: 75 (Method, 2026)
• a Temple Incursion: 175 (Method)
• the Ancient Foe that follows a successful Incursion: 200 (Method)

The same coins buy the points of Spirit Corrosion at the altar next to the vendor at a rising price (the Venomous Coiler's notes have 1,000 for the first and 20,000 for the last), and every five points spent raise the coins found, up to +225% (Wowhead's guide). Method advises buying altar points first for that reason; no source says how much sooner the mount comes that way. Whether coins earned on several characters can be pooled was seen only in a search excerpt of another site and not checked.

The Skull also sells two pets, four ensembles, an arsenal and housing decor for the same coins (Method).

Confidence in this entry: medium. Looked up in 2026.

Sources

• Wowhead: caustic venomfang
• Wowhead: vaults of atalutek patch 12 1 zone activities rewards player power
• Wowhead tooltip: quest 98388
• Wiki: Caustic Venomfang
• Wiki: Vaults of Atal'Utek
• Method: caustic venomfang mount guide
• Method: skull of er inye corrosive coins vendor location and rewards in wow midnight
• Method: how to farm corrosive coins in wow midnight