Chaos Hound

The Chaos Hound is a boss fought at the end of Golden Sun: Dark Dawn. It is a twisted, burly werewolf-like creature that Blados and Chalis control like a pet, and all three fight the party in the first of the two final boss battles.

After Blados and Chalis are defeated, but not necessarily the Chaos Hound, the duo use their Dark Psynergy to empower the Chaos Hound, which causes it to grow in size and absorb the duo's bodies, creating a multi-armed monstrosity. After the party defeats it, Sveta discovers that it is the twisted body of her brother, Volechek, who Tuaparang captured and "improved" after Volechek turned against them at the start of the Grave Eclipse. Being a creature of darkness now, Volechek will not be able to exist in the normal light-filled world, but he is able to survive long enough in the dangerous amounts of light permeating Apollo Lens in order to turn it on and end the Grave Eclipse.