The words that can be used as synonyms for the "dubious flying fox" are skeptical fruit bat, mistrustful bat, uncertain bat, doubtful flying mammal, and suspicious nocturnal creature. These terms convey the same sense of doubt, hesitation, and lack of confidence that the phrase "dubious flying fox" does. Just like the original phrase, they can be used to describe a situation, behavior, or personality of an individual or group that is not fully trusted. Whether it is the distrust towards the flying mammals themselves or towards the opinions they represent, the synonyms for "dubious flying fox" capture the essence of uncertainty and hesitation that this phrase implies.