Doomsday

Doomsday is a villian of DC Comics and is one of greatest enemies of Superman.

History
The nameless being later to be called Doomsday (by Booster Gold) was artificially created in the distant past on Krypton, long before the humanoid Kryptonian race had gained dominance over the planet. During this time period, Krypton was a violent, hellish world where only the absolute strongest of creatures could survive (at the time, the world's dominant lifeforms were said to be the most dangerous creatures in the universe). Doomsday's creator was a mysterious alien named Bertron, who wished to create the ultimate life-form. To do so, Bertron and his team sent a baby onto the surface of the planet, where it would be instantly killed by the harsh environment or the vicious creatures inhabiting it. Each time, whatever of the lifeforms remains that survived were harvested and used again, to create a better, stronger version than the previous. In short, the mad scientist was using the method of cloning to accelerate the evolution of the being he was creating. Through decades of this process, the being who would eventually become Doomsday was forced to endure the agony of death, thousands upon thousands of times; the memory of these countless deaths was recorded in his genes and drove it to hate all life. Eventually, Doomsday gained the ability to evolve against what killed him in his prior life without the need of Bertron's technology. At this point he proceeded to hunt down and kill all of the lethal creatures that inhabited Krypton. When it saw Bertron, Doomsday considered him and the team to be a threat due to their roles in his multiple deaths and attacked the ship they were working in. Bertron himself met his death at the hands of his own creation.

Crossover Appearances
Multiverse: Crash of Universes