Lucan [1st century CE] (Pharsalia, book 9, verse 921-926): How prospered Murrus when his lance transfixed / A basilisk ? Swift through the weapon ran / The poison to his hand : he drew his sword / And at one blow he swept the limb away : / So did he live and gazed upon the hand / Which dying paid his ransom. - [Ridley, 1919, Volume 2, Page 245]

Pliny the Elder [1st century CE] (Natural History, Book 8, 33; 29, 19): [Book 8, 33] The basilisk serpent also has the same power. It is a native of the province of Cyrenaica, not more than 12 inches long, and adorned with a bright white marking on the head like a sort of diadem. It routs all snakes with its hiss, and does not move its body forward in manifold coils like the other snakes but advancing with its middle raised high. It kills bushes not only by its touch but also by its breath, scorches up grass and bursts rocks. Its effect on other animals is disastrous: it is believed that once one was killed with a spear by a man on horseback and the infection rising through the spear killed not only the rider but also the horse. Yet to a creature so marvelous as this indeed kings have often wished to see a specimen when safely dead. The venom of weasels is fatal: so fixed is the decree of nature that nothing shall be without its match. They throw the basilisks into weasels' holes, which are easily known by the foulness of the ground, and the weasels kill them by their stench and die themselves at the same time, and nature's battle is accomplished. [Book 29, 19] The basilisk, which puts to flight even the very serpents, killing them sometimes by its smell, is said to be fatal to a man if it only looks at him. Its blood the Magi praise to the skies, telling how it thickens as does pitch, and resembles pitch in color, but becomes a brighter red than cinnabar when diluted. They claim that by it petitions to potentates, and even prayers to the gods, are made successful; that it provides cures for disease and amulets against sorcery. Some call it "Saturn's blood." - [Rackham translation]

Aelianus [170-230 CE] (On the Characteristics of Animals, Book 2, 5; 3, 31): [Book 2, 5] The Basilisk measures but a span, yet at the sight of it the longest snake not after an interval but on the instant, at the mere impact of its breath, shrivels. And if a man has a stick in his hand and the Basilisk bites it, the owner of the rod dies. [Book 3, 31] ... the Basilisk too, they say, goes in fear of the [cock]: at the sight of one it shudders, and at the sound of its crowing it is seized with convulsions and dies. This is why travelers in Libya, which is the nurse of such monsters, in fear of the aforesaid Basilisk take with them a cock as companion and partner of their journey to protect themselves from so terrible an infliction. - [Scholfield translation]

Gaius Julius Solinus [3rd century CE] (De mirabilibus mundi / Polyhistor, Chapter 27.50-53): [Chapter 27.50] ...the basilisk, an evil unique in all the lands. [Chapter 27.51] It is a serpent, almost half a foot in length; its head is lined, as though with a little white head-band. It is given to the destruction not only of men and other living things, but also of the land itself. Wherever it chooses to make its toxic den is polluted and burned. It devastates vegetation and kills trees, and also contaminates the very breezes. So it is that no bird can fly unharmed over air infected by its unwholesome breath. [Chapter 27.52] When it is agitated, it crawls along with one half of its body, and rears the other half up high. Even serpents recoil in terror from its hissing, and when they hear it, they all hurry to flee in any possible direction. [Chapter 27.53] Anything that dies from its bite is not devoured by wild beasts or touched by birds. Nevertheless, the basilisk is defeated by weasels, which men in those parts stuff into the caverns in which it takes shelter. Yet it does not lack power even when dead. Indeed, the Pergamenes acquired, for a pretty penny, the remains of a basilisk, so spiders would not spin on their shrine, famous for the workmanship of Apelles, nor birds fly into it. - [Arwen Apps translation, 2011]

Isidore of Seville [7th century CE] (Etymologies, Book 12, 4:6-9): [Book12, 4.6] Basilisk (basiliscus) is a Greek word, translated into Latin as “little king” (regulus), because it is the king of the snakes, so that they flee when they see it because it kills them with its odor – it also kills a human if it looks at one. Indeed no flying bird may pass unharmed by the basilisk’s face, but however distant it may be it is burnt up and devoured by this animal’s mouth. [Book 12, 4:7] However, the basilisk may be overcome by weasels. For this reason people take weasels into caves where the basilisk lies hidden; and as the basilisk takes flight at the sight, the weasel chases it down and kills it. Thus the Creator of nature sets forth nothing without a remedy. It is half a foot in length, and marked with white spots. [Book 12, 4:8] Basilisks, like scorpions, seek after parched places, and when they come to water they become hydrophobic and frantic. [Book 12, 4:9] The sibilus is the same as the basilisk, and it kills by means of a hissing, before it bites and burns. - [Barney, Lewis, et. al. translation]

Alexander Neckam [1147-1217 CE] (De naturis rerum, Book 2.120): The basilisk is a singular evil on earth. It is a serpent nearly half a foot in length, given not only to the destruction of man or of other living creatures, but also of the earth, which it pollutes and burns, wherever the wild animal finds shelter. In fact it scorches the grass, kills the trees, and even corrupts the winds themselves, so that no bird in the air flies over with impunity. When it moves, it crawls with the middle of its body raised high and tall. Even other serpents are horrified at its hissing; and when they hear it, they hasten their flight with all possible means. Whatever it kills with its bite, other beasts do not eat, and birds not even touch it. It is, however, defeated by weasels, which men bring into the caves in which the basilisk hides. However, even the when dead it does not lack strength. Indeed, the Pergamenes procured the remains of a basilisk, at great cost, so that spiders would not weave webs in the shrines created by Apellis, nor would birds enter. - [Wright/Badke]

Theophilus Presbyter [c. 1070–1125] In the Schedula diversarum artium the alchemist known as Theophilus tells of how "the heathen, who are said to be skilled in this art, produce basilisks for themselves in this way. They have a structure under the ground, made above, below and all round with stones, with two tiny openings, so small that scarcely any light can be seen through them. In this they place two old fowls, twelve or fifteen years old, and they give them plenty to eat. When they have become plump, with the heat of their fatness they copulate and lay eggs. When these have been laid, the fowls are taken away and toads are introduced to sit on the eggs, and bread is given them for food. When the eggs are hatched, male chicks emerge like hens' chicks. After seven days they grow the tails of serpents. If the structure were not paved with stone they would immediately enter the ground. Careful of this, their owners have round bronze vessels of large size, perforated everywhere and with narrow mouths, and they place the chicks in these, block up the mouths with copper lids, and bury them in the ground. For six months they are nourished with the fine earth entering through the holes. After this, they uncover the vessels and place them on a large fire until the beasts within are completely burned. When this has been done and the vessels have cooled, they take them out and carefully grind them, adding a third part of the blood of a red-headed man, which has been dried and ground. These two compounds are mixed with sharp vinegar in a clean vessel. Then they take very thin sheets of pure red copper, and they smear this preparation over them on each side and put them on the fire. When they are white-hot, they take them off and quench them in the same preparation and wash them, and so they proceed for a long time until this preparation eats through the copper, which, thereupon, takes on the weight and color of gold. This gold is suitable for all work." - C.R. Dodwell translation

Hildegard von Bingen [1098-1179 CE] (Physica, Book 7.): The basilisk is born from certain vermin that are somewhat diabolical, that is, from toads. Sometimes, when the toad has been impregnated and is going to bring forth young, if she sees the egg of a serpent or hen, she loves it and lies over it. She warms it until she gives birth to her naturally conceived young. These die as soon as they are born. Seeing them dead, she again places herself over the egg and warms it until the young in that egg has begun to live. Soon, a particular power of the diabolic art of the ancient serpent touches it. This power rests in the Antichrist, and just as he resists all heavenly beings, so this animal fights against all mortals, killing them. After the toad senses that the thing in the egg is alive, she is immediately astounded by this unusual occurrence and flees. The animal breaks through its shell and emerges. It naturally sends out very strong breath, similar to thunder and lightning. The fire within it can be very fierce and strong, without the torments of Tartarus. It comes from its shell and with its breath it splits the earth almost to the depth of five cubits. It then lies in this split of moist earth until it grows to maturity. Then it climbs back up to earth, killing with its breath all the living things it finds. Nothing living desires, nor is able, to endure it. When it sees something that is alive, in its displeasure it sends cold and then its breath, so killing the creature it blew on. It falls immediately, as if struck by thunder and lightning. If a basilisk has died in any field or vineyard, and its cadaver has rotted there, that place will be unfruitful and sterile. If it dies and rots in any citadel or house, the people there will always be ill, and the animals-in that place will frequently get disease and very often die from it. - [Throop translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Serpents 8.4): Basiliscus, as Jacobus says, is a serpent, which is said to be the king of serpents. Hence basiliscus in Greek is the same as regulus [king] in Latin. The basilisk is therefore an evil on the earth. It is half a foot in length, marked with white spots on the head like a sort of diadem; it breaks rocks with its breath. Other snakes fear and flee from this snake, because it kills them with a single breath. But it kills men by sight alone. For if it sees a man first, the man dies; but if a man first sees the serpent, the serpent is killed, as Jacobus says. Pliny seems to hint at the same thing, when he first says of the animal cathapleba [catoblepas], that it kills men on sight, and adds: The same power is in the basilisk serpent; and later in book 29: it kills a man with a look. How this can be done, the Experimentator explains in his book. For he says that the rays from the basilisk's eyes corrupt the visible spirit of man, by which other spirits are corrupted, which descend from the brain and the life of the heart; and so a man dies. Basilisks, like scorpions, stalk each other; and - after they have reached the waters - they produce dropsy and lymphatics. Nor is it given to the destruction only of man (the basilisk) or of other living creatures, but also of the earth, which it pollutes to death and burns up every place the wild beasts seek shelter. Finally, it burns the grass and the trees themselves, it kills bushes, it breaks rocks; it also corrupts the winds to such an extent that no bird flies through the air with impunity, because it is infected with a pestilential spirit. When it moves, the middle part of the body crawls. Even the other serpents are terrified at its hissing, and when they hear it they make haste to flee wherever they can. Whatever it kills with its bite is not eaten by wild animals, nor do they touch it. It is, however, overcome by weasels, which men bring into the caves in which the basilisk hides. When basilisks are killed, as Pliny says, the weasels also die, and the battle is finished by nature. For it was decided that nothing should be without a match, so that it could not be overcome by another natural enemy. However, even a dead basilisk does not lack strength. For wherever its ashes are spread, spiders cannot weave nor produce any poison. It was said that a temple in Greece was covered with this ash. And this is said to be true of whatever part of its body is kept. Indeed, it is said that silver, painted with the ash, becomes the color of gold. There is a kind of basilisk that flies, but does not go beyond the limits of its region, which the divine ordination has established for them so that they do not turn to ravage the world. There is also another kind of basilisk, and there is a description of that in the book De volucribus ['on birds'] in the chapter De gallo ['on the cock']. - [Badke translation/paraphrase]

Albertus Magnus [ca. 1200-1280 CE] (De animalibus, Book 23, 51; 24, 18): [Book 23, 51] Some writers claim an old rooster can by itself produce an egg and deposit it in a dung heap; while this egg lacks a true shell, its outer skin is tough enough to resist the strongest blows; from the heat of the dung this egg supposedly hatches into a basilisk which in all respects looks like a cock, except that its tail is elongated like a snake. Personally I do not credit this as a true story, but in fairness it was told by Hermes and believed by many readers because of the authority of the writer. [Book 24, 18] Basilisk is the snake which in Latin translation is called "regulus", but has the same sound in Greek, "basiliscus". Moreover, there is a second reason for its name, for it seems to have a crowned head; on top of its head it has a dotted design picked out in white and hyacinth colors, which gives the serpent the appearance of being crowned with a royal diadem encrusted with glittering gems. The length of this serpent is two palm’s-breadths, its head is quite pointed, its eyes are red, its color varies from black to ashen-gray, and its breath scorches everything in its vicinity, so that nothing whatsoever grows in a circular area around its lair, because it sears trees, bushes and plants, breaks up stones and infects the very air, to the point that a bird flying over its habitation summarily falls dead; the same misfortune awaits other beasts and snakes with the sole exception of the "armene", which in many respects bears an affinity to the basilisk. The basilisk also kills with its hissing [sibilo], provided it raises itself erect, because the hissing is propelled by its breath and kills at least within the distance that its breath is able to travel. I doubt that the basilisk is lethal to anyone who is merely within hearing distance of its sound; more likely, its pernicious influence is limited to those within range of its breath. Furthermore, it kills by its gaze, for everyone on whom its fixed stare falls dies as a result. Pliny and some other writers maintain that the basilisk strikes a man dead with its gaze only if it spies the man first; contrariwise, if the man makes the initial visual contact, his gaze kills the basilisk [usually said of the snake]. I do not think this is true, because it has no basis in reason. Neither Avicenna nor Semerion, both of whom are natural philosophers who speak from experience, tell this story. Nor is the reason it kills by its gaze, as some allege, because rays emitted from its eyes destroy those upon whom they fall. The opinion of natural scientists is that rays do not emerge from the eyes; rather, the cause of the corrupting influence is the visual energy [spiritus visivus] which is diffused over very long distances because of the subtlety of its substantial nature; herein lies its ability to destroy and kill everything. All other snakes fear and flee from this serpent, with the exception of the one we named above, and even this one flees on occasion. No matter what animal it bites, the results are the same; the victim’s body becomes edematous and swells; the poison courses through the body and death ensues almost immediately. If another man approaches the victim, he dies as well; if the victim is prodded with a long lance or spear, the bearer of the lance dies; this once happened to a soldier who touched a poisoned victim with his lance, and his horse also died when its lips accidentally brushed the same lance. This serpent abounds in the land of the Turks and in Nubia. According to reports, the weasel kills this serpent. When local inhabitants find themselves overwhelmed by a multitude of basilisks, they let loose weasels into the serpents’ dens; the serpent tries to escape, but in the end the weasel slays it. If this account is true, it seems to be well nigh miraculous. They claim that wherever the ashes of a basilisk have been scattered, no spiders weave their webs nor do other venomous creatures appear; hence, the ancients strewed basilisk’s ashes in their temples. Hermes asserts that silver melted in the ashes of a basilisk takes on the splendor, weight and density of gold. Some authors allege that there is a certain type of basilisk which can fly, but I have not been able to confirm this in the texts of the most reputable philosophers. Furthermore, some writers claim that basilisks are generated from the egg of a rooster; this is patently false, if not downright impossible. - [Scanlan]

Bartholomaeus Anglicus [13th century CE] (Liber de proprietatibus rerum, Book18.16): The Cockatrice is called Basiliscus in Gréeke, and Regulus in Latine, and hath that name Regulus of a litle king, for he is King of serpents, and they are afeard and flye when they sée him, for he slayeth them with his smell and with his breathe: and slayeth also all thing that hath lyfe, with breathe and with sight. In his sight, no fowle, nor birde passeth harmelesse, and though he be farre from the foule, yet it is burnt and deuoured by his mouth. But he is overcome of the Wesel: and men bring the Wesell to the Cockatrice denne, wherin hée lurketh and is hidde, for the Father and maker of all thing, lefte nothing without remedy: and so the Cockatrice flieth when he séeth the Wesell, and the Wesell pursueth and slayeth him: and the Cockatrice is halfe a foote long, and hath white speckes: and the Cockatrice slayeth that that he commeth nigh, as the Scorpion, and that water that hée toucheth, maketh the Dropsie, and it is venemous and deadly. And some men call the Coackatrice Sibilus, for with hissing he slayeth, ere he biteth or stingeth. Huc usque Isidorus. lib. 12, capitulo. 4. Plinius also sayth, libro. 8. capitulo. 22. Among the Hisperies and Aethyopes is a well, that many men suppose is the head of Nylus, and there beside is a wilde beast that is called Catobletas, and hath a lyttle body, and nice in al members, and a great head hanging alway, toward the earth, and els it were great noyeng to mankinde: for all that sée his eyen, should dye anone, and the same kinde hath the Cockatrice, and the Serpent that is bred in the Province of Syrena, and hath a bodye in length and breadth as the Cockatrice, and a tayle of twelve inches long, and hath a specke in his head as a precious stone, and feareth away all Serpents with hissing, and he presseth not his bodye with much bowing, but his course of way is forth right, and goeth in meane: he dryeth and burneth leaves and hearbes, not onely with touche, but also by hissing and blast, he rotteth and corrupteth all thing aboute him. And he is of so great venime and perillous, that he slayeth and wasteth him yt commeth nigh him by the length of a speare, without tarrieng. And yet the Wesell taketh and overcommeth him: for it pleaseth God, that no kindly thing should be without peere, for the biting of the Wesell is death to ye Cockatrice: and neverthelesse the biting of the Cockatrice is death to the wesell, & yt is sure, except ye wesel eat rew before. And against such venime, as Aristotle sayth and Avicen[na], first the Wesell eateth the hearb of Row, though it be bitter, and by vertue of the juyce of that hearb, be goeth boldly and obey commeth his enemie. And though the Cockatrice be venomous without remedy, while he is alway, yet he léeseth all the malice, when he is burnt to ashes: his ashes are accounted good and profitable in workeing of Alkamie, and namely in turning and changing of mettall. - [Batman]