Kirk Langstrom is a scientist who has inadvertently transformed himself into a vampire in an attempt to cure his cancer, feeding on criminals to satisfy his hunger becoming Batman. He is one of the main protagonists in Justice League: Gods and Monsters Chronicles, and Justice League: Gods and Monsters.
Kirk was a graduate from Gotham University with his friends Will Magnus and Tina Magnus. He studied science in an effort to find a cure for his cancer. Believing he had found the cure to his condition, he used this nanite-infused serum on himself, only to find he had an insatiable hunger for blood, akin to a vampire. He was taken in by Superman and became a member of the Justice League, feeding on criminals and other wrongdoers to satisfy his bloodlust.
Despite his lack of social skills and his blood lust, Kirk is very polite to civilians, and even feels guilt about killing criminals. As Batman, he is willing to kill people gruesomely and suck their blood, but he feeds only on criminals. Whenever he interacts with civilians or other superheroes, he is a pretty decent person, if a bit asocial, and saves innocents like any superhero would.
- This version of the character is exclusive to the continuity of the film Justice League: Gods and Monsters and is an adaptation of Kirk Langstrom. The original character was created by Frank Robbins and Neal Adams and first appeared in Detective Comics #400.