Variations: Presteros, Torridus (Torrid), Dipsas (Thirsty)


The Prester, “bellows-swelling”, “swollen veins”, or “inflater”,  is a deadly species of asp found in the deserts of Libya. Its name is derived from the gruesome effects of its venom, which were experienced firsthand by Lucan’s men. Aldrovandi believed it to be the same as the Dipsas, while Topsell saw it as distinct, since the prester kills by heat while the dipsas uses thirst.

Presters are so torrid that they keep their steaming mouth open to cool off, and foam constantly bubbles out from inside them. Topsell identifies presters with the fiery snakes that plagued the Israelites in the wilderness, but does not describe them beyond their extreme internal heat. They are fast-moving snakes, hurrying from place to place with their panting mouths wide open.

Aelian described the prester’s venom as causing profound lethargy, progressive weakness, loss of memory, inability to urinate, hair loss, choking, and eventually convulsions that lead to death. Flaubert specifies that mere contact with it causes debilitation.

Lucan describes more grotesque symptoms. The unfortunate Nasidius, upon suffering a scorching prester’s bite, feels the flames of the venom coursing through his veins. His entire body starts to swell, inflating and bloating and cutting through his armor, engulfing his limbs. The tumorous swelling ends only once Nasidius is a formless, headless heap. The remains are so disgusting that even the scavengers shun them.

Topsell recommends wild purslane, castoreum or beaver-stones, opoponax and rue in wine, and sprats as a remedy for prester bite.


Aelian, trans. Scholfield, A. F. (1959) On the Characteristics of Animals, vol. III. Harvard University Press, Cambridge, Massachusetts.

Aldrovandi, U. (1640) Serpentum, et Draconum Historiae. Antonij Bernie, Bologna.

Batinski, E. (1992) Cato and the Battle with the Serpents. Syllecta Classica, Vol. 3, pp. 71-80.

Eldred, K. O. (2000) Poetry in Motion: the Snakes of Lucan. Helios 27.1, p. 63.

Flaubert, G. (1885) La Tentation de Saint Antoine. Quantin, Paris.

Isidore of Seville, trans. Barney, S. A.; Lewis, W. J.; Beach, J. A.; and Berghof, O. (2006) The Etymologies of Isidore of Seville. Cambridge University Press, Cambridge.

Lucan, trans. Rowe, N. (1720) Pharsalia. T. Johnson, London.

Topsell, E. (1658) The History of Serpents. E. Cotes, London.