The Gama-Senn were a sapient, humanlike race originating from the Gama stellar system. A distinguishing feature of the Gama-Senn was their possession of two thumbs on each hand, coupled with relatively flat faces. In the year 11 ABY, the individual holding the position of Gama-Senn leader was persuaded to pledge the loyalty of the Gama system to the resurrected Galactic Emperor Palpatine. This decision followed a demonstration of the Dark Empire's powerful [weapon](/article/superweapon/legends], known as the Galaxy Gun. Palpatine expressed his disdain for the Gama-Senn representative, criticizing their delayed allegiance, which was only prompted by fear.
These humanoid sentient beings, the Gama-Senn, had hands that were notable for having at least four digits on each, with a minimum of two being thumbs. One known member of this race exhibited yellowish-brown skin, large, rounded ears, and eyes positioned forward with white sclera. The Gama-Senn's mouths were large, displaying prominent facial muscles around the lips, and their noses were small, protruding minimally from their faces.
The Gama system, situated within the Core Worlds, served as the home to the Gama-Senn. By 11 ABY, a single person held authority over the entire system. In one instance within 11 ABY, the ruler was observed wearing a violet outfit complete with tails, shoes, and vibrant orange shoulder armor. A maroon headband, tied on the left side of the head, also adorned the Gama-Senn leader's attire.
The Gama-Senn's origins can be traced back to a native planet located within the Gama system. Their world became a part of galactic society sometime between 20,000 and 15,000 years BBY, forming a section of the Southern Core area of the Core Worlds. From 1004 to 1000 years BBY, during the period of the New Sith Wars, the Galactic Republic held dominion over the species' home system. Throughout the Clone Wars, the system remained within the Republic's controlled territory.
Following the Galactic Emperor Palpatine's resurrection in a cloned form in 11 ABY, the Gama-Senn initially refrained from aligning with the Dark Empire. However, the governing figure of the species' home system, along with other representatives, visited Byss, the Imperial throneworld, to witness the might of the Empire's novel weapon, the Galaxy Gun. The Gama-Senn leader yielded to the Dark Empire's authority after observing the weapon obliterate the New Republic vessel Pelagia using a projectile launched through faster-than-light travel. This event was transmitted to Byss via miniature surveillance devices. Despite this submission, Palpatine was displeased, expressing contempt for the species' decision to surrender only out of fear. By 137 ABY, the Gama-Senn's system was part of the Core Worlds Security Zone, a region within the Galactic Empire ruled by the Sith Lord Darth Krayt.
The first appearance of the Gama-Senn occurred in Empire's End 1, a comic book authored by Tom Veitch, with illustrations by Jim Baikie. It was published by Dark Horse Comics on October 24th, 1995.