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.
Behind the scenes
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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.
