The Muuns, a slender and elongated humanoid species, were in charge of the InterGalactic Banking Clan.
Recognized across the galaxy as avaricious bankers, the Muuns were a pale, lanky humanoid species. Their height was accentuated by their extended craniums. The bald heads of Muuns had small eyes positioned above a lengthy, subtle nose, which frequently imparted a nasal tone to their speech. Their diminutive, flattened ears were located beneath the edge of their skull. Their slender arms were of typical length, terminating in hands with five digits. The final pair of digits on each hand were notably shorter than the others. Unlike certain other humanoid species, neither gender among Muuns possessed noticeable breasts. Beneath their lean midsection were a couple of exceptionally long, thin legs. As a species, they were highly intelligent and renowned for their exceptional mathematical skills. These skills were especially valuable for managing the InterGalactic Banking Clan.
The typical Muun's height was just shy of 2 meters. Some Muuns, such as Nix Card, were known to reach heights of up to 2.46 meters. Members of the species could connect with and manipulate the Force.

The planet Scipio was the homeworld of the Muuns. The Muuns gained control of the InterGalactic Banking Clan and built their empire high up in the snowy mountain peaks. A Muun family raised Senator Rush Clovis.
A Muun was trained by Darth Tenebrous, the Dark Lord of the Sith, sometime before 132 BBY, and adopted the name Darth Plagueis. After succeeding Tenebrous as the Sith Master, Plagueis took on Sheev Palpatine as his apprentice, giving him the title Darth Sidious. Together, they advanced their order's grand plan to infiltrate the Galactic Republic and replace it with a restored Sith Empire. Plagueis also investigated the Force, conducting experiments with midi-chlorians and researching the Doctrine of the Dyad and transference, hoping to find the key to immortality. Although he did not achieve this goal, he was successful in paving the way for Palpatine's rise to political prominence. Sidious murdered him in his sleep by 32 BBY, having learned everything Plagueis had to teach him.
During the Clone Wars, the Galactic Republic and the Confederacy of Independent Systems both invested heavily in soldiers and weaponry, spending significant amounts of credits. Clovis, a human, represented the organization in the Galactic Senate before being replaced by Nix Card when he fell from grace. After his return to political life, Clovis became the head of the IGBC after their governing body, the Core Five, were arrested on charges of corruption. Mak Plain supported Clovis, but Clovis was killed during the Battle of Scipio. San Hill, a Muun who served as Chairman of the IGBC and also sat on the Separatist Council, was killed at the end of the war.

Muuns continued to work for the Banking Clan during the New Republic Era. Around 9 ABY, some Muuns paid a formal visit to the planet Lanupa, staying at Skull Ridge Mountain Hotel & Spa. Several Muuns, including a male and a female, relaxed in a mud bath during their leisure time.