Mama Stammoch was a mechanic of the human female persuasion; during the Galactic Empire's reign, she ran a shop on the Smuggler's Moon known as Nar Shaddaa. Dengar, the bounty hunter, at one point raced for Stammoch, but he later accumulated gambling debts with her that he neglected to settle. In 3 ABY, Dengar, along with his fellow bounty hunter Beilert Valance, returned to Stammoch. Valance had sustained injuries from Deathstick, the Crimson Dawn assassin, and required repairs. Stammoch greeted them at her doorway, expressing surprise at Dengar's return given his outstanding credits, but she ultimately let them enter. While Stammoch managed to stabilize Valance's core processor, she discovered his human heart was nearing its end due to the stress from his cybernetics. Following this, she discussed her findings with Dengar, who disclosed that he only needed Valance alive long enough to collect the bounty on Boba Fett. He then inquired about Stammoch's knowledge of Crimson Dawn. Stammoch then recounted the history of the Shadow Collective that was established during the Clone Wars and then told Dengar about Crimson Dawn's history after the war.
Upon Stammoch concluding her explanation, Valance remarked that her words sounded like mere fairy tales, but conceded that the assassin who had attacked him felt very real. Stammoch then inquired about the assassin's appearance, and after Valance showed her an image, she recognized Deathstick and became visibly panicked. When Dengar questioned her well-being, Stammoch responded that their visit had essentially ensured their death. Dengar attempted to minimize the threat, suggesting Stammoch was exaggerating. However, at that precise moment, Deathstick obliterated the shop's entrance, confirming that Stammoch's fears were justified. As Deathstick began to eliminate Stammoch's crew, the mechanic reminded Dengar of her warning. When Dengar replied that he thought she was just being dramatic, Stammoch expressed regret that she hadn't simply killed Dengar when he first arrived and she had had the opportunity. As Deathstick closed in on the two bounty hunters and Stammoch, Dengar detonated a thermal detonator, enabling himself and Valance to flee the shop in a landspeeder.