A basilisk is a mythical monster with a form resembling a snake. The name derives from the Greek word basilískos meaning “little king” or “little prince.” References to basilisks appear as early as the first century CE, when the Roman author Pliny the Elder mentioned them in his encyclopedia, Natural History. Pliny and subsequent Classical and medieval authors, such as Isidore of Seville and the Venerable Bede, wrote about the basilisk as a real animal, although it gradually shifted into being treated as a legendary monster. The idea of a basilisk may have emerged from descriptions of cobras: venomous snakes whose hoods display distinct markings which may resemble a crown (leading to descriptions of mythical basilisks with crowns or “crests”). There are four species of lizard which belong to the genus Basiliscus, including a species known as the common basilisk.

In addition to being extremely poisonous, the mythological basilisk was reputed to have the ability to kill with its gaze (a feature that Straube incorporates into her novel). In some versions of the myth, it can also breathe fire. Due to the deadly gaze, some legends depict a basilisk being killed with a mirror. Although Straube depicts basilisks as capable of shifting between snake and human form, the mythology surrounding basilisks does not typically include this attribute. Basilisks were sometimes conflated with cockatrices, mythical creatures with the head of a rooster atop the body of a serpent or lizard. However, other legends treated the two as separate, with basilisks hatching from the egg of a serpent incubated by a chicken, while cockatrices hatched from a chicken egg incubated by a serpent or toad. The combined mythology of chickens and snakes and possible hybrid forms is reflected in Straube’s plot and depiction of Tem as a “hybreed.”

A number of authors reference basilisks in works of literature, often focusing on the power of the creature’s dangerous gaze. In William Shakespeare's Richard III (1597), Anne Neville, upon hearing seductive compliments about her eyes from her husband's murderer, retorts that she wishes they were those of a basilisk, that she might kill him. Bram Stoker’s novel Dracula (1897) depicts the titular vampire’s chilling gaze via an allusion: “the eyes fell upon me, with all their blaze of basilisk horror” (Oxford World’s Classics, pg. 52). Basilisks also appear in the Harry Potter series, notably in Harry Potter and the Chamber of Secrets (1998). In the Harry Potter novels, basilisks are depicted as giant snakes who can kill with their gaze.