Metallo
Metallo is a radioactive cyborg intelligence who depends on Green Kryptonite as his energy source. He is a former soldier who was used in experimentation by the United States Army, eventually giving him the ability to project his consciousness into any technological device.
First Appearance: Action Comics #252 (1959)
Creators: Robert Bernstein, Al Plastino
Powers: Cybernetic Enhancement
Black entries are ongoing series
Green entries are Limited series
Red entries are One-Shots
Orange are alternate universe stories
Blue is for comments
Reading Order
Action Comics #252 – First appearance of Supergirl, Metallo
Superman #423 – Whatever Happened to the Man of Tomorrow?
Superman Vol. 2 #1 (1987)
Superman Vol. 2 #2
Adventures of Superman #441
Superman Vol. 2 #20
Superman: Secret Origin #6
Superman #651
Action Comics #851
Action Comics Annual #11
Action Comics Vol. 2 #1 (2011)
Action Comics Vol. 2 #2
Action Comics Vol. 2 #3
Action Comics Vol. 2 #4
Action Comics Vol. 2 #8
Action Comics Vol. 2 #23.4 – Metallo
Forever Evil #1 (2013)
Justice League of America Vol. 3 #8
Forever Evil #4
Read Superman: Doomed here.