Trawak

Trawak was a language spoken by the Trawaki, a cave-dwelling species that independently evolved on the world Rushan IX. According to the protocol droid C-3PO, the language supposedly involved ultrasonics, replication of sounds from the environment, and subtle interactions between air and mouthparts. The Trawaki became extinct over a thousand years before the Imperial Era, and their language fell into obscurity, though it was contained within the databanks of the Autonomous Translator Module, Mark II. When wishing to create unbreakable encryption codes following the Battle of Hoth, the Rebel Alliance intended to steal the linguistics droid and utilize its knowledge of Trawak as the basis for a new code. After the rebels retrieved the droid, they discovered it had become corrupted, and were thus unable to use the language. But after repairing it and with some help from Lobot the language was put into use as a new code with C-3PO using his more advanced systems and special traits built in by his creator and learnt how to speak the language so he could make the code translations himself.