The following is a description from the Dumfries Herald in 1859 of an encounter between an Adder and a Weasel:-

FIGHT BETWEEN AN ADDER AND A WEASEL

Two or three parties – a farmer and servant, – came on an adder and a weasel at drawn daggers, on a spot behind Craignair quarries, Buittle.  The weasel was the aggressive party very evidently, and the adder acted purely on the defensive.  The weasel now inflicted a wound immediately behind the adder’s head, then retired cautiously, studying his opportunity. Again he attacked the adder’s tail, and then its back, and in this manner kept up a hot fight.  The adder was evidently willing to wound, and indulged in twistings and convolutions ; but the weasel was too adroit for him in his flank and front movements.  The parties saw them fight it out, and took up the adder (the weasel having left the field) quite dead, and his back riddled with weasel bites.