Kerastes

A kerastes or cerastes (Greek: κεράστης 'having horns', English: cerastēs) is a serpent that is incredibly flexible—so much so that it is said to have no spine. Kerastai can have either two large ram-like horns or four pairs of smaller horns. The kerastes hides its head in the sand with only the horns protruding out of the surface; this is meant to deceive other animals into thinking it is food. When a curious animal approaches the horn, the kerastes promptly jumps from the sand and kills its prey.

Leonardo da Vinci wrote the following on the kerastes:"This has four movable little horns; so, when it wants to feed, it hides under leaves all of its body except these little horns which, as they move, seem to the birds to be some small worms at play. Then they immediately swoop down to pick them and the Cerastes suddenly twines round them and encircles and devours them."

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It is most likely derived from the habits of the horned viper (whose genus was named Cerastes after it). They are desert-dwelling snakes which can have horn-like protrusions over their eyes and are ambush predators, though not nearly large enough to take prey much larger than a mouse or small lizard.