- Real Name: Chemo
- Alias: Chemo
- Identity: Public Identity
- Alignment: Bad
- Gender: Male
- Hair: None, Eyes: Green
- Occupation: Sentient Chemical Being
- First appearance: Showcase #39 (July, 1962)
Chemo was originally a huge plastic vessel, about twenty-five feet tall and roughly man-shaped, built by eccentric scientist Ramsey Norton to contain the chemical by-products from his failed experiments to better motivate him to eventual success. The scientist met with failure after failure in his experiments, but pressed forward. Chemo became filled with greater and greater quantities of various chemicals.
After attempting to create a growth formula that would enlarge plants to help feed starving nations, the scientist again was unsuccessful and poured the remnants of his project into Chemo, finally filling the massive vessel. These chemicals caused a massive reaction that resulted in Chemo coming to life and growing into a building-sized giant. Chemo proceeded to poison the scientist with a lethal dose of the growth-formula chemicals and then went on a rampage, only to be defeated by the Metal Men.
Chemo proved to be an impressively resilient monster. Being a unique form of pseudo-life, it could not really die. It returned time and time again, undergoing various resurrections and mutations, and had several more encounters with the Metal Men as well as squaring off against Superman more than once. During the Crisis on Infinite Earths, Brainiac and Lex Luthor used Chemo as a living weapon stationed on Earth-Four. Chemo proceeded to destroy much of that earth's New York City and poisoned Aquagirl by spewing more than a dozen varieties of corrosive acids into the ocean. It was finally destroyed when Negative Woman of the Doom Patrol used her energy powers to shatter Chemo's living plastic shell.
After the Crisis, Chemo again was resurrected and fought against a variety of superheroes, starting with the Metal Men and Superman, after it had used Superman's skin cells to regrow itself. It was defeated and dispersed, and would not appear again for a long time.
Chemo eventually reformed itself in Leesburg and was collected by a chemical company there. Chemo naturally escaped and began to tear up part of the town before being confronted by Supergirl, who had recently become the merged being of the Matrix and Linda Danvers. Chemo was surprised with Supergirl, as she did not seem to "fit" exactly into the category of a human being. When Supergirl told Chemo it was not really alive, but merely a collection of chemicals, it screamed and dispersed itself into the atmosphere, creating a harmless rainstorm in the process.
It has also fought with Superman as part of the Suicide Squad formed by President Lex Luthor to break Doomsday out of his prison at the Justice League Watchtower teleporters.
During the Infinite Crisis, The Society used Chemo as a living chemical weapon and dropped him onto the city of Blüdhaven, killing millions of people. The irony of this event is seen through the eyes of Nightwing.
He had agreed with Deathstroke for a 72 hour ceasefire in Blüdhaven in exchange for staying away from Rose Wilson. However, Chemo was dropped before the 34th hour. Chemo bathed the entire city in radiation and toxic waste. All able-bodied superheroes attended to save the infected, but Chemo was reforming itself. Superman battled the monster with the plan that he would regenerate quicker as the battle ensued. While Chemo regenerated, he continued to suck the toxins and radiation out of the city, freeing the city of the remaining radiation and waste. In the end, Superman lifts Chemo and throws him into outer space, freeing the destroyed city of Blüdhaven from Chemo.
Since then, The Outsiders encountered Chemo in space while Batman was holding auditions for his new team. Chemo was seen again as a member of Lex Luthor's new Injustice League. He was also seen as one of the villains deported in "Salvation Run."