Nyarchagga is a Dug scoundrel who was the slave of Zorba the Hutt, father of Jabba the Hutt. He was born into slavery on the planet of Nal Hutta. The Hutt decided to have Nyarchagga trained in computer slicing, droid programming and repair, and security systems.
Nyarchagga, however, didn't want to be a slave, so he used his skills of computer slicing and security systems to escape from Zorba and his men as well as disable the device that would explode inside him if he ran away. Zorba, angered at Nyarchagga's treachery, hired bounty hunters to hunt him down and kill him. Nyarchagga was finally caught on Nar Shadaa where he was going to be executed by the bounty hunters.
However, Jin Tai Lo and Brin'tac Kyen'tir were looking for information from some spy on Nar Shadaa who might tell them more about where Brin'tac's family might be. While searching for the place where they were supposed to meet this spy, they ran across Nyarchagga who was about to be killed. Jin Tai Lo, seeking to spare the Dug's life, intervened. Nyarchagga, in return for saving his life, offered to aid Master Lo and Brin'tac in their search with whatever skills he could offer them. Since then he has travelled with Brin'tac and Master Lo using his skills in computer slicing and security systems to help.
Because of the fact that he was a slave, Nyarchagga is used to serving others, and so when he offered his services to Brin'tac and Jin Tai Lo he fell right back into that role once more. He now serves Brin'tac almost as a dependent slave rather than an independent being. However, Brin'tac has been working with Nyarchagga to become more independent because he feels that it is best for the Dug to be free of that lifestyle. Therefore, Dug and Brin'tac have become really good friends as well as companions on their search for Brin'tac's family.
Nyarchagga has also created a droid companion for himself named GNAT. This droid is used for spying. It is created in the shape of a beetle about the size of a human palm, and it hovers above the ground up to about ten feet high. Its only equipment is a holo-recorder and projector as well as a vocabulator with which it can speak to Nyarchagga about what it has learned or seen. This droid was an invaluable instrument for the successful escape of Nyarchagga from his slave masters, and Nyarchagga would just as soon part with his left upper appendage than part with GNAT.