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.
You can only create this portal when playing at a difficulty level you have already completed. For example, you 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 (virgin kill) 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 a novelty and a treat and not a place to endlessly exploit for massive experience gain.
- Blizzard constantly states that "there is no Cow Level".
- There were many rumors that there was a "Secret Cow Level" in the original Diablo. These rumors were false and it is believed that the reason the "Secret Cow Level" was made was to appeal to fans.
- 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 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 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!"
- One item set, the Cow King's Leathers, can only be found in the Secret Cow Level.
- The Rabies Werewolf build is very useful in this level.
- 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.
- 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.
| Diablo II|
Pandemonium Event Zones — Matron's Den • Forgotten Sands • Furnace of Pain • Über Tristram
Easter Egg Zones — Secret Cow Level
Easter Egg Zones — Whimsyshire