Doomsday is a near-unstoppable monster that exists solely to kill and destroy everything in its path. Based on the character from DC Comics, this incarnation of Doomsday appeared in Zack Snyder's DC Extended Universe film Batman v Superman: Dawn of Justice. The origins of this version of the character differ significantly from the original; while the Doomsday of the comics was engineered by an alien scientist on prehistoric Krypton, this incarnation of Doomsday was created by Superman's arch-nemesis Lex Luthor using both Kryptonian and human DNA.
Doomsday's vocals and motion-capture were provided by voice actor Robin Atkin Downes.
In Batman v Superman: Dawn of Justice, Lex Luthor had devised an insidious plot to kill Superman and discredit him in the eyes of the human race. Originally, he had planned to force both Superman and Batman into a conflict, hoping that the Dark Knight would use the Kryptonite he provided to slay the Man of Steel. In the event that Batman failed, however, Luthor also developed his own means of destroying Superman. Using the Kryptonian technology aboard the Fortress of Solitude and the corpse of General Zod, Luthor was able to recreate an ancient Kryptonian genetic experiment, creating a deformed abomination capable of untold destruction using Zod's corpse and his own blood.
Superman and Batman stopped their fight after Batman realised that Luthor had been holding Clark Kent's mother Martha hostage. Whilst Batman rescues Martha from Anatoli Knyazev, Superman confronts Luthor just as he completes the birthing process of the Kryptonian deformity. The monster stirs and awakens which Luthor gleefully proclaims as "Superman's Doomsday".
Doomsday unleashes a thunderous roar, and hurls a monstrous punch at Lex. However, the punch is intercepted by Superman, who blocks and counters with a blow of his own. The battling duo then proceed to break out of the Fortress of Solitude, continuing their mortal duel.
Doomsday breaks free of the Fortress of Solitude and leaps into Heroes Park. Superman pursues Doomsday, and the two do battle, Doomsday destroying the Superman Statue in the process. Doomsday's strength surpasses Superman's, but he manages to hold his own and sends the creature flying into a building. Subsequently, Doomsday is fired at by military helicopters, but is not harmed. He adapts to the fire and only becomes more durable.
Doomsday is then launched into space by Superman. The US President then sends an order to shoot Doomsday down with a nuclear missile, carried out by General Swanwick. Seeing the missile approach, Superman defiantly holds Doomsday still, determined to destroy the beast. The warhead hits with an explosion so gigantic, that it can clearly be seen from Earth's surface.
Falling back to Earth, Doomsday's body lands on Stryker's Island, but is far from dead. The explosion seemingly only making the creature stronger. Doomsday's body once again regenerates. Recovered himself, Superman then charges at Doomsday yet again, sending the beast flying where it collides with a chemical silo. Batman attempts to distract Doomsday, but is eventually cornered. Doomsday shoots his heat vision at him, however the rays are deflected by Wonder Woman.
Superman and Wonder Woman then proceed to attack Doomsday in tandem, while Batman tries to expose the monster to the Kryptonite gas. Superman then leaves to save Lois Lane from drowning and retrieves Batman's Kryptonite Spear. Batman is successful in exploiting Doomsday's only known vulnerability. Seeing her chance, Wonder Woman attacks and manages to cut off the creature's arm. However, it only results in a sharp skeletal protrusion growing back in its place.
Wonder Woman manages to temporarily restrain Doomsday with her lasso. Superman sees that the only way to stop Doomsday is to risk his own life. He charges at the creature, exposed to the Kryptonite himself, and stabs Doomsday in the chest with the Kryptonite Spear. The spear did not manage to fully pierce Doomsday and he is able to stab Superman in return, piercing his chest with the bone protrusion on his arm. A mortally wounded Superman is undeterred by his impending death, and he uses his last reserves of strength to further impale Doomsday and manages to fully push it through the other side, finally killing the monster, though himself dying in the process. With a final bellow of agony, the now lifeless bodies of hero and monster collapse upon the ground.
What becomes of Doomsday's corpse after its titanic duel with Superman is unknown. It is also unknown if Doomsday is truly dead since it is capable of adapting to any form of attack used against it and can regenerate its injuries. The original comic book version of Doomsday has repeatedly come back to life after each death, immune to whatever had previously killed it. it is not yet known if the DCEU version of Doomsday is equally immortal.