Villain file · 07

Metallo.

A cyborg with a kryptonite heart.

The file

The facts, in one place.

Metallo is John Corben, a cyborg powered by a kryptonite heart that fires radiation at Superman. He first appeared in Action Comics #252 (May 1959), by Robert Bernstein and Al Plastino, the same issue that introduced Supergirl. Superman stops him by shielding him with lead or by removing the kryptonite.

First appearance: Action Comics #252, 1959

Through the years

Every era, a new plan.

Silver Age (1956–1970)
John Corben debuts in Action Comics #252 (May 1959), by Robert Bernstein and Al Plastino. A 1942 villain called Metalo (George Grant, World's Finest Comics #6) is a different character.
Post-Crisis (1986–2011)
John Byrne revamps him in The Man of Steel (1986) and Superman (vol. 2) #1 (1987). Later versions add shape-shifting and technomorphing.
Film and TV
Scott Valentine in Lois & Clark, Brian Austin Green in Smallville and Frederick Schmidt in Supergirl; Malcolm McDowell voiced him in Superman: The Animated Series.

The full file

The whole story.

Most villains need to find some kryptonite. Metallo carries it inside his chest. His power source is the one thing guaranteed to weaken Superman.

Who is Metallo?

Metallo is John Corben, a man rebuilt as a cyborg. His body is powered by a kryptonite heart, which also lets him fire kryptonite radiation. Later versions add shape-shifting and technomorphing.

Metallo’s first appearance

John Corben first appeared in Action Comics #252 (May 1959), by writer Robert Bernstein and artist Al Plastino. It’s a famous issue for another reason too: it also introduced Supergirl.

Don’t mix him up with Metalo (one “l”), George Grant, who appeared in World’s Finest Comics #6 in 1942. He’s a different character.

Powers

Power	Detail	Confidence
Cyborg body	Superhuman strength	Confirmed
Kryptonite heart	Powers him and fires kryptonite radiation	Confirmed
Later upgrades	Shape-shifting and technomorphing	Confirmed

How Superman beats him

The published answer is simple: cover Metallo in lead, which blocks the radiation, or take out the kryptonite that powers him. Lead is also what Superman’s X-ray vision can’t see through, so it turns up in many of his stories.

After Crisis

John Byrne revamped Metallo in The Man of Steel (1986) and Superman (vol. 2) #1 (1987).

Key stories

Three great places to start:

Action Comics #252 (May 1959): John Corben’s Silver Age origin, in the same issue as Supergirl’s debut.
Superman (vol. 2) #1 (January 1987): John Byrne’s post-Crisis Metallo, kryptonite heart and all. The classic modern version.
“Rise of Metallo”, Action Comics #1051–1056 (2023): Phillip Kennedy Johnson’s modern take, praised by reviewers.

“Best” is a judgement call, so treat these as recommendations (Likely).

Metallo on screen

Scott Valentine played him in Lois & Clark, Brian Austin Green in Smallville and Frederick Schmidt in Supergirl. Malcolm McDowell voiced him in Superman: The Animated Series. For other villains who drain or poison Superman, see Parasite and Superman’s villains.

Questions