Sullin was a female non-humanoid who lived in the Delta Quadrant in the 24th century and was a member of the Think Tank. A jellyfish-like coelenterate lifeform, she had to be suspended in a tank of liquid, and she communicated with her fellow group members with the use of a device on their ship that allowed them to communicate telepathically. She was an expert of temporal physics, and was regarded by Kurros as one of the most gifted members of their group. It was Sullin who solved the geostability problem facing Saowin's planet by finding the precise harmonic for a planetary containment field.