A seps is a legendary snake from medieval bestiaries. They were said to have extremely corrosive venom that liquefied their prey. [1]
Lucan's Pharsalia refers to its appearance and the effects of its poison.
... Clinging to his skin
A Seps with curving tooth, of little size,
He seized and tore away, and to the sands
Pierced with his javelin. Small the serpent's bulk;
None deals a death more horrible in form.
For swift the flesh dissolving round the wound
Bared the pale bone; swam all his limbs in blood;
Wasted the tissue of his calves and knees:
And all the muscles of his thighs were thawed
In black distilment, and file membrane sheath
Parted, that bound his vitals, which abroad
Flowed upon earth: yet seemed it not that all
His frame was loosed, for by the venomous drop
Were all the bands that held his muscles drawn
Down to a juice; the framework of his chest
Was bare, its cavity, and all the parts
Hid by the organs of life, that make the man. [2]
Shelley in Prometheus Unbound writes:
Similarly, the seps is described as "a small snake which consumes with its poison not just the body but the bones" in the medieval Aberdeen Bestiary . [4]