Huh, the Japanese version of the Pallas's Cat's name is its Scientific name (+ cat), or at least the language's best go at it with its given phonemes.
Both pallas cat and manul/manul cat are correct names in English language. "Manul" is a derivation of Mongolian name for the species, and is used in its scientific name. This name is also more prevalent in eastern languages. "Scientific" names are just Latin, and they use loanwords very often.