After the Summoning Wars
Also called "Star Baby", this creature is believed to be an entire sentient demiplane in humanoid form. It now walks the Material Plane.
This creature appears to be a human male in his mid-40s. He is entirely bald, and rail-thin. He wears a plain brown tunic and carries his street-sweeping broom, with no other possessions.
First Encounter: Session 10 when the party interacted with the residents of an odd and surprisingly malleable town. They came to the conclusion that the town (and surrounding area) were simply the projections of a semi-sentient demi-plane. They taught it new things, and dubbed it “Mystique”. Thomas and Bert convinced the street-sweeper to join them on the material plane as an ambassador.
In Session 15, Meerkin claimed that Mystique had spent some time with him after separating with the party, but that Thomas had come to retrieve it. They were apparently bound for Myria. Obviously, that Thomas was not the real one.