The secret cow level, or simply the cow level, is a level featured in the action role-playing hack and slash video game series Diablo, developed and published by Blizzard Entertainment. It first appears as postgame content in 2000's Diablo II, where it is officially known as the "Moo Moo Farm". Players may access the level after collecting a special combination of items to conjure a portal leading to the level. The player character is confronted upon arrival by a large horde of armed anthropomorphic cows led by a boss character called the "Cow King".
The cow level originated as a hoax about a secret level perpetrated by players of 1997's Diablo, and has been described as one of the most famous and well-known urban legends related to video gaming by publications. The attention surrounding the hoax influenced developers to acknowledge it as an inside joke by seeding Easter egg references in related games during the late 1990s: the Diablo expansion pack Diablo: Hellfire, and 1998's StarCraft. The level's appearance in Diablo II marked the first instance of the hoax being developed into actual in-game content. Fan appeal for the cow level affected later Blizzard titles, which led to similarly themed levels appearing in Diablo III and World of Warcraft, as well as several imitations and recreations in other video games.
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