10 Amazing Video Game Moments Created By Fans

7. Diablo II's Secret Cow Level

Now technically speaking, Diablo II's infamous Secret Cow Level was developed entirely by the fine folk at Blizzard, but it never would have come to pass had fans not first dispersed the myth that the original Diablo featured said cow level.

The urban legend dictated that players could click on the corpse of a cow and be transported to a special land filled with the animals, a prospect so ridiculous that it quickly took on a life of its own with fans, even though it absolutely wasn't true.

Blizzard had plenty of fun teasing fans about the level's non-existence, even including a cheat code in their game StarCraft - activated by typing "there is no cow level" - and publishing what appeared to be a photo of a Secret Cow Level on April Fools' Day 1999.

But when Diablo II hit stores the next year, it turned out not to be a prank at all - the Secret Cow Level allowed players to battle hordes of "Hell Bovines", and even a cow boss called The Cow King. Nice.

But the Secret Cow Level never would've come to pass had a daft fan not propagated the ridiculous rumour in the first place. Whoever you are, thank you.