

The character was voiced by Jim Edwards, a programmer who worked on Hellfire.

The hoax was first acknowledged by the Synergistic Software-developed expansion pack, Hellfire, as a quest which features a non-player character dressed in a cow suit with cow-themed dialogue. Screenshots of the purported level, which were created with Photoshop to show a red-hued portal and demonic enemies lifted from unused game assets, emerged and circulated online. Clicking on one of the cows numerous times is supposedly capable of summoning a portal to a secret level. The cow level originated as a player rumor about a herd of cattle in the town hub area of 1997's Diablo. 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. The level's appearance in Diablo II marked the first instance of the hoax being developed into actual in-game content. 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 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 player character is confronted upon arrival by a large horde of armed anthropomorphic cows led by a boss character called the "Cow King". Players may access the level after collecting a special combination of items to conjure a portal leading to the level. It first appears as postgame content in 2000's Diablo II, where it is officially known as the " Moo Moo Farm". 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. The player character surrounded by Hell Bovines inside Diablo II 's cow level
