Jamirus

Jamirus is one of the four Dread Fiends and a major villain in Dragon Quest VI. He's a cunning three-eyed gryphon who's an adept at giving speeches to his fellow monsters and coming up with schemes to round up victims for sacrifices in the name of the Archfiend.

Story
He devised a plan in which he used his monster minions disguised as humans and a moving island to lure the people from the town of Aridea to a make-believe land of fantasy and happiness called the Isle o' Smiles, which supposedly appears at night only. As soon as the gullible townspeople reached their destination, which is really a demonic shrine, they got sacrificed to the dark gods.

After he's defeated by the heroes, the dream selves of all who were sacrificed are set free. That includes King Medfordand his palace, who's now avaliable for the Hero to bring in his Mini-Medals. The hero also gets to keep the moving island, which can be used as a boat in the Dream World.

Other appearances
In Dragon Quest Monsters: Joker 2, he is a cohort of Gemon and can be obtained through synthesis using a Pazuzu and a Gryphon.