The Eradicator is a fictional comic book superhero (and sometimes supervillain) character having a recurring role in Superman stories published by DC Comics. Originally created as a weapon by an ancient alien race, he is over 200,000 years old and is considered an artifact of Krypton. The character was created by writer Roger Stern, and first appeared in Action Comics Annual #2 (1989).
In the distant past, a dying alien race creates a number of containment devices in which to preserve their culture. They send them into space with contact teams, intent on meeting other civilizations. When a small group of these aliens arrive on the planet Krypton, they are met by the militant Kem-L, who kills them and corrupts one of the devices. Its new mission is to preserve his ideal of Kryptonian culture by eradicating all others — and thus the device becomes known as the "Eradicator."
In its original form, the Eradicator resembles a stylized small rocket. Its top section is a prolate spheroid, which exudes a blue glow and is approximately three times the size of an egg. This is connected via four thin mount brackets to a glossy orange tail fin section of equal length. The ten equally spaced fins each have the shape of a pointed quarter ellipse, with the tapered end extending slightly beyond the rear of the squat main cylindrical body tube.
On Krypton, the Eradicator does all that it could over the years to protect Kryptonians, even from themselves. When a group of Kryptonian explorers leave Krypton in search of a new planet to colonize, the Eradicator alters their birthing matrices and makes them fatally allergic to lead, thus creating Daxamites. To further ensure that nobody left Krypton, the Eradicator alters Kryptonians so that they will instantly perish if they leave their world.
One of the surviving aliens, known as the Cleric, takes the Eradicator and leaves Krypton with a group of followers. Unfortunately, they die soon thereafter, as the Kryptonian genetic link to their home planet precludes their survival off-world. The Cleric keeps the Eradicator for 200,000 years, until he encounters Superman on Warworld.With the device, the two exchange memories, and the Cleric has a vision of Superman in combat with Mongul. The Cleric wishes to save Superman's life, and the Eradicator transports Superman to the Cleric's asteroid. The Cleric notices that the device has changed to protect Krypton's sole survivor, and he and Superman use it to heal their wounds, both physical and spiritual. When the Cleric gives the Eradicator to Superman, he rapidly ages and dies as the link to the Eradicator extending his life is severed