The ReAnimen are creations of the criminal scientist D.A. Sinclair. They are former humans altered by Sinclair into mechanical, zombie-like creatures. Following his arrest, Sinclair was reformed and enlisted by the G.D.A. to produce an army of ReAnimen to be employed as weapons against the impending danger of the Viltrum Empire. More advanced and stronger versions were developed, utilizing consenting corpses in their production instead of living subjects.