The Secret Cow Level, also known as the Moo Moo Farm, can be found in Diablo II (with or without the expansion Diablo II: Lord of Destruction). To create a portal to the secret level, combine Wirt's Leg and a Tome of Town Portal in the Horadric Cube. A red portal will appear in the Act I starting area.

Players can only create this portal when playing at a difficulty level they have already completed. For example, one must first beat the game (through Act IV in the original game or Act V in the expansion) on Normal difficulty before you can create the Secret Cow Level in a game of Normal difficulty.

The Secret Cow Level is a small area, full of Hell Bovines: bipedal cattle with polearms. A rather special cow, named "The Cow King", always appears in the level. If someone kills the Cow King for the first time on the current difficulty, all players within the Cow Level, partied or not, will get "the kill" (he/she will be unable to create another portal to the Secret Cow Level on the same difficulty). Furthermore, if someone already has killed the Cow King on the current difficulty in a previous game and decides to kill the King in another game, everyone within the Cow Level will be ineligible to get "the kill."

The cow level was the most popular place to level up in Patch 1.09, due to the huge numbers of cows, and the fact that their slow speed, low resistances, and clumping behavior made them very easy to kill in bunches. The experience and item gains possible in the level were nerfed in Patch 1.10, and the level returned to its intended purpose as balanced and not a place to endlessly exploit for massive experience gain, thus avoiding more difficult grinding.

In Diablo II: Resurrected, The Secret Cow Level can be terrorized. Due to the aforementioned nerfs to experience, the experience gained from terrorized cows is not particularly impressive. Nonetheless, the Secret Cow Level is one of the best places to farm items even when it is not terrorized, and it become terrorized makes running it even better.

The Secret Cow Level is considered one of the most popular terror zones by Blizzard, and therefore it is terrorized often during the 22 Nights of Terror holiday event that occurs annually in December, on days designated "Winter Terrorland".

In Diablo II: Resurrected – Reign of the Warlock, whether by design or not, using a Western Worldstone Shard does not cause the Secret Cow Level to become terrorized, despite it terrorizing the rest of Act I. Despite the Secret Cow Level being an excellent place to farm items, particularly when terrorized, it is a poor zone to attempt to spawn heralds of terror from, thanks to the low number of bosses (6-8 in hell difficulty).

Trivia

This section contains facts and trivia relevant to this article.

• One item set, the Cow King's Leathers, can only be found in the Secret Cow Level.

Origins

The concept of the cow level dates back to Diablo I, where a rumor emerged that if a player clicked on a cow a given number of times, the player would be taken to a "Cow Level."^[1]

• In Diablo: Hellfire, the Jersey's Jersey quest was created to reference the rumor.^[2]
• The level was implemented in Diablo II in light of the original rumor.^[1]
• A variation of this level, called "No Level Name" can be made if the portal maker creates the level at the boundary of the Rogue Encampment and the Blood Moor.
• The Hell Bovines' first victim was Wirt, which could explain why his peg-leg is the key to 'The Secret Cow Level'.
• Upon entering the "Secret Cow level" portal "Entering moo moo farm" is shown.

Cultural References

Blizzard Games

• One of the tooltips on Diablo III loading screen states: "Cow level is a lie". This appears to be a reference to the famous Portal game series line "The cake is a lie".
• A free web enhancement called To Hell and Back, available at the Wizards of the Coast site, contains the Secret Cow Level with statistics for the enemy cows.
• One of the cheat codes on StarCraft, "There Is No Cow Level", was made to confirm there was no cow level made. Later on it was still added.
• There is a leather chest armor item in the World of Warcraft called Cow King's Hide, an obvious reference to the secret level.
• In the Warcraft III: Frozen Throne chapter Curse of the Blood Elves, there is a secret level that could be accessed to unlock Blizzard's version of a Tower Defense. In the course of unlocking, many sheep are involved, which brought up the 'Secret Sheep level', a reference to the Secret Cow Level.
• In Warcraft III, you can find "Wirt's Other Leg" which, of course, is a reference to "Wirt's Leg" and in turn is a reference to Wirt in the first game.
• In Starcraft II, it is possible to join the "Cow Level" chat room, although not by ordinary means.
• In World of Warcraft, you can obtain an item called "Wirt's Third Leg".
• A "secret cow level" has been discovered for Diablo III, accessed though the help of the Ghost of the Cow King.
• In Reaper of Souls there is a Cow Level in the Act V Nephalem Rift in Adventure Mode.
• The Cow Level logo has been used for promotion of an unannounced Blizzard project.^[3]
• A "Not So Secret Cow Farm" can be found in Goat Simulator, as accessed from a town called "Twistram." Bi-pedal cows attack the goat by shooting lasers from their udders.^[4]
• For a short time in January 2017 to celebrate Diablo's 20th Anniversary, World of Warcraft players who completed Legion dungeons would spawn a naughty Treasure Goblin. Defeating him would reward some additional loot and open a portal to a place that has long since only been rumored to exist—the infamous Cow Level. Killing the Cow King will reward a unique toy and a Feat of Strength. Slaughter enough goblins and you'll be able to complete a Tome of Town Portal toy or collect a 28-slot Horadric Satchel.
• In the World of Warcraft expansion Battle for Azeroth there is an achievement Lactose Intolerant  that can be earned while fighting a boss that will allow players to briefly transport to a secret cow level.  Slaughter enough cows and you'll earn the achievement which will yield progress towards a special mount. 

Other

• In Matthew Reilly's novel, The Six Sacred Stones, a pair of twins (who aid the main characters) frequently sport shirts that say "I have seen the Cow level!" and subsequently "There is no cow level!"
• In Marvel Heroes 2015, there is a "Classified Bovine Sector" accessible via special portal, that leads to an updated version of the level, with the boss cow being "High Commander Brevik." There is also a new, winter cow level, named "Bovenheim" that is much bigger and has a new boss, "All-Father Brevik".^[5]
• A Secret Cow Level features in It Lurks Below.^[1]

References