| crotalus | (n) large rattlesnakes; seldom bite unless startled or pursuing prey, Syn. genus Crotalus |
| canebrake rattlesnake | (n) southern variety, Syn. canebrake rattler, Crotalus horridus atricaudatus |
| diamondback | (n) large deadly rattlesnake with diamond-shaped markings, Syn. Crotalus adamanteus, diamondback rattlesnake |
| mojave rattlesnake | (n) extremely dangerous; most common in areas of scattered scrubby growth; from Mojave Desert to western Texas and into Mexico, Syn. Crotalus scutulatus |
| old world white pelican | (n) similar to American white pelican, Syn. Pelecanus onocrotalus |
| prairie rattlesnake | (n) widely distributed between the Mississippi and the Rockies, Syn. Western rattlesnake, Crotalus viridis, prairie rattler |
| rock rattlesnake | (n) mountain rock dweller of Mexico and most southern parts of United States southwest, Syn. Crotalus lepidus |
| sidewinder | (n) small pale-colored desert rattlesnake of southwestern United States; body moves in an s-shaped curve, Syn. Crotalus cerastes, horned rattlesnake |
| speckled rattlesnake | (n) markings vary but usually harmonize with background; of southwestern Arizona and Baja California, Syn. Crotalus mitchellii |
| tiger rattlesnake | (n) having irregularly cross-banded back; of arid foothills and canyons of southern Arizona and Mexico, Syn. Crotalus tigris |
| timber rattlesnake | (n) widely distributed in rugged ground of eastern United States, Syn. Crotalus horridus horridus, banded rattlesnake |
| western diamondback | (n) largest and most dangerous North American snake; of southwestern United States and Mexico, Syn. Western diamondback rattlesnake, Crotalus atrox |