A diamondback is a type of venomous rattlesnake with distinctive diamond-shaped markings along its back. The eastern diamondback, found in the southeastern United States, is one of the largest rattlesnakes in North America, sometimes growing over six feet long. The western diamondback lives in the southwestern states and Mexico. Both species get their name from the bold, diamond-like pattern on their scales.

Like all rattlesnakes, diamondbacks have a rattle at the end of their tail that makes a buzzing sound when shaken, warning other animals to stay away. They're pit vipers, meaning they have special heat-sensing organs that help them hunt warm-blooded prey like rabbits and rats, even in complete darkness.

Diamondbacks play an important role in controlling rodent populations. While their venom is dangerous, they generally try to avoid humans and only strike when they feel threatened or cornered.

The word also appears in the names of sports teams, like the Arizona Diamondbacks baseball team, chosen because the desert is home to western diamondback rattlesnakes.