Your first foreign swear word? *toothy grin*
Yeh - it means “stupid animal.” Japanese has no proper swear words so that’s as bad as it gets natively, although the language is flexible enough to import them at need. “You sunnabeech!” never fails to get send us Gaijin off howling with laughter. (It is, as are all foreign-origin words, properly written in Katakana...) ;-)