The Undead King

is the 1st light novel volume in the

Overlord series.

It was released on July 30, 2012. It details about Satoru Suzuki, whose game avatar known as

Momonga

, a player of

YGGDRASIL

suddenly finds his consciousness trapped in his avatar and all of the NPCs around him begins to gain sentience. He must struggle to find a way to survive this new world.