Your request was diamonback which is probably a typo from diamondback.
diamonback -
Traditional English :: diamondback
diamonback - n. 1 an edible freshwater terrapin, Malaclemys terrapin, native to N. America, with lozenge-shaped markings on its shell. 2 any rattlesnake of the genus Crotalus, native to N. America, with diamond-shaped markings.