Marker was employed as the president of a bank in Manhattan, NY. However, his personal fortures dwindled and he faced bankruptcy, and so he recruited a criminal gang and began to plot crimes. Marker took his nom du crime, the Adder, not from any poisonous snakes, but rather from the fact that he contacted his men through a series of personal ads in the local newspaper. A large part of their success was that Marker planned the robberies to affect only his own bank, and any kidnappings would be of Marker's social acquaintances with money, so that he could plot these crimes effectively.
Ultimately, Marker and his gang were stopped by the Crimson Avenger I and his Asian partner, Wing. During the battle, Marker fled into the subway system, with the heroes giving chase. Marker accidentally stepped onto the third rail and was electrocuted, and the Crimson Avenger unmasked him after he died. The remaining members of his gang escaped, but were later rounded up by the local authorities.
- enemy of Crimson Avenger
- This version of Marker (Earth-Two), including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 1 Appearances of Marker (Earth-Two)
- 1 Images featuring Marker (Earth-Two)
- Quotations by or about Marker (Earth-Two)
- Character Gallery: Marker (Earth-Two)