Annihilus

[kandrathe]

The rumour I've heard is that it is the reward for battleing the Diablo Clone(s). I suspect it's a new "Cow Level" but only accessible once you have beaten all three Prime Evils. I think one of the modders had commented that it is in it's own treasure class and the Diablo Clone was the only monster with that class.

I've no idea how to activate it, or where this battle might occur.