Julian Lamprey was a Lamprey.
He and his sister entered our universe through a cave in 12th century England. They looked like green-skinned human children. Richard de Calne named them Julien and Dominique after his grandparents, and took care of them for several weeks.
Julien eventually became ill from being away from his home environment, his skin changing to a normal human colour. They went back to the cave through which they entered our reality, but it had been sealed by Shepherd Mullen. Before it could be opened again, Julien died. (PROSE: Spiral Scratch)