horned viper, cerastes, sand viper, horned asp, Cerastes cornutus
['American alligator, Alligator mississipiensis', 'thimble', 'chiton, coat-of-mail shell, sea cradle, polyplacophore', 'feather boa, boa', 'tree frog, tree-frog', 'echidna, spiny anteater, anteater', 'flatworm, platyhelminth']