Doctor Ernest Calderon (p layed by Gerard Plunkett) was an alien/human hybrid who worked at the Prangen pharmaceuticals company and provided special medical service to Emily Sim as part of the Syndicate's hybridization experiments. Scully met him while investigating the murder of Marshall Sim's wife (TXF: "Christmas Carol"). A man identical to Doctor Calderon is seen arresting Jeremiah Smith at the Social Security Administration office in Washington, D.C. in 1996 (TXF: "Talitha Cumi"). This seems to imply that Calderon was part of a clone series doing various tasks for the Syndicate.