Catharese
From Wookieepedia, the Star Wars wiki.
Catharese was the native language of the Cathar. Communication in Catharese included remarking some spoken words with a growl. Cathars were usually also fluent in Basic.
[edit] Behind the scenes
In Knights of the Old Republic, the Cathar Jedi Juhani speaks Basic, albeit with what can be considered a Russian accent, with rolled "r"s and "w"s that sound like "v"s. It is possible that this is meant to represent a Catharian dialect of Basic.
