Slayer

Description
The Slayer is a creature sent by the demons to slay the Reaper of the Twin Serpent Mountains. It resembles a Hellhound and it is not confirmed whether it is undead or demon.

Note: despite the name of the associated quest, the Slayer is a Warrior, not an Assassin.

Location

 * The Underworld: Running up the Twin Serpent Mountains as soon as the quest Demon Assassin is taken.