Yuzzum, a language, was utilized by the Yuzzum species. These beings were native to Endor's moon, and shared a mutual understanding with the vibrant Ewokese tongue of the Ewoks, who also originated from Endor. C-3PO, the protocol droid, employed Yuzzum when he communicated with the Ewoks residing in Bright Tree Village.
In the Star Wars Insider 218 article "Rewind of the Jedi," a factual error claims that C-3PO spoke Ewokese in the film Return of the Jedi.