Sources : Spoliator colubri

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Worms 9.41): The spoliator colubri [spoiler of snakes] is a worm, as he says [i.e. Liber rerum], of a golden color, whence it is called by some 'golden worms' [vermis aureus]. It is also shaded with green. This snake killer is said to have its name from its nature, for when it sees a snake lying down, it climbs on its tail and runs over to its head, and first soothes it by rubbing; at last it attacks the snake's flesh with bites. And when the snake feels the injury, it tries to escape by running away, but in vain, for the pursuer follows the fleeing one and takes the fatal bite, until it penetrates the interior of the brain and destroys the snake and is satisfied with its flesh. Thus the small and weak worm overcomes the serpent by cunning. And hence it is that the worm itself was called a serpent. Of this worm Aristotle seems to say that it is surprising to many; and he says that when these worms, which he calls golden in color, are born, they are fed first by their parents, then they remain without food for many days and thus lie motionless and seem dead. But after the time which nature has fixed for them, they revive and rise to provide themselves with food. - [Badke translation/paraphrase]