The Fantastic Mister Jackal, or "Let sleeping foxes lie"

Foxes feature prominently in two mishnayot in Avot. In Avot 2:15 Rabbi Eliezer ben Hyrcanus warns against getting over-familiar with the Chachamim since (among other things) their bite is like the bite of a fox. Later, in Avot 4:20, Rabbi Masya ben Charash teaches that it is better to be the tail of a lion than the head of a fox. 

The meaning of each mishnah is quite easy to accept at face value. In the first, we are warned to expect a sharp, snappy response from a learned rabbi if we speak with him in a manner that is less than respectful. In the second, we understand that it is better to be even an insignificant part of a noble enterprise than to lead a crafty, perhaps disreputable one. Foxes, after all, bite and are cunning. 

Professor Yehuda Felix however puts the metaphorical cat among the pigeons when he argues (HaChai BaMishnah, 1972, cited by Avigdor Shinan, Pirush Yisraeli Chadash at Avot 4:20) that the word shu'al -- normally translated as "fox" -- in mishnaic times referred to the jackal. While both are members of the canine family, the jackal is larger, carries a far more powerful bite that can deliver rabies, and was found widely in the area in the era of the Mishnah and Talmud. 

It has been accepted for close on two thousand years that "fox" means "fox" and not "jackal". While the jackal would fit well in Rabbi Eliezer's mishnah, he is not a byword for cunning and would therefore seem somewhat out of place in Rabbi Masya's mishnah.  Maybe it is best to let sleeping foxes lie ...