Pokémon Snakewood is a Rom-Hack of Pokémon Ruby by Cutlerine.
In Pokémon Snakewood, the player wakes up to see Hoenn invaded by zombies. The player is tasked to find out what happened, and to find your brother and Professor Birch's daughter. However, this hack's fairly known for going off the rails beyond this premise, having a rambling sort of plot about the four horsemen of the apocalypse, the king of dragons Meteor, and a demigod called Senex.
Pokémon Snakewood consists of zombified versions of canon Pokémon and some completely new Fakemon, as well as some normal Pokémon.