Attuma Duum was a pirate and cyborg, as well as a dealer of weapons and a war profiteer. He experienced death but was subsequently reconstructed into a cyborg body before the events of 21 BBY. During the Clone Wars, he manipulated both the Galactic Republic and the Confederacy of Independent Systems, drawing two fleets to his headquarters located in an asteroid field. In the midst of the conflict, he encountered both Aayla Secura and Shon-Ju, but managed to survive.
Sometime before 21 BBY, Attuma Duum was killed, only to be brought back to life with a cyborg body. Only his face remained organic. He concealed his cyborg nature. Over the years, a multitude of assassins were dispatched to eliminate him, including flesh-eating nanobots, brain-snipers originating from Latza VII, and a creature known as a Xandonian night terror.
During the Clone Wars, he established his base within an asteroid field situated close to the moon of Cavamina Minor. To capitalize on the war, he provided intelligence to both the Galactic Republic and the Separatist Alliance. He tricked both a Republic and Separatist fleet into coming to his base, where he ambushed them using a minefield.
Before the battle, Duum, aided by his friend and head of security, Sabat, had captured two individuals who were Force-sensitive. These captives broke free, killed Sabat, and confronted Duum. Duum fought Shon-Ju in single combat, but Shon-Ju gained the upper hand. Aayla Secura stepped in to prevent Shon-Ju from completely destroying Duum's damaged body. Duum then fled in a Class-6 escape pod, escaping his doomed base. Despite the collapse of his empire, Duum intended to rebuild it.
Following his resurrection, he adopted a nonchalant attitude towards death. He used a blond wig and fine clothing, including a costly cape, to mask his appearance from the galaxy at large. Duum was strongly motivated by credits, and he willingly played both sides of the war against one another, finding the deception enjoyable. He overestimated his combat skills against Shon-Ju and ran away after Secura intervened to stop Shon-Ju from killing him.
Attuma Duum makes an appearance in the 2010 graphic novella titled The Clone Wars: Deadly Hands of Shon-Ju. The summary located on the back of the novella contains a misspelling of his name, rendering it as "Atuma Duum".