Know your meme gives the English caption as "Watch out guys, we’re dealing with a badass over here", which google translate (and some native French dictionaries) renders as "attention les gars, nous avons affaire à un dur à cuire ici". If you separate bad and ass, you get mauvais âne, but that suggests a case of the farmer's rather than the proper meaning of the American idiom "bad ass"
Know your meme gives the English caption as "Watch out guys, we’re dealing with a badass over here", which google translate (and some native French dictionaries) renders as "attention les gars, nous avons affaire à un dur à cuire ici". If you separate bad and ass, you get mauvais âne, but that suggests a case of the farmer's rather than the proper meaning of the American idiom "bad ass"