This is to see which one gets to win the competition for a viable female mate. Its tail is typically a different shade than its body, ranging from brown to gray and banded with dark rings. Eastern Diamondback Rattlesnake. The color pattern of the typical form, C. o. oreganus, has a dark-brown, dark-gray, olive-brown, or sometimes black or pale yellowish ground color overlaid dorsally with a series of large, dark blotches with uneven white edges.These blotches are also wider than the spaces that separate them. I've never heard of this snake before, but apparently they are pretty common in Texas. The eastern diamondback rattlesnake inhabits upland dry pine forest, pine and palmetto flatwoods, sandhills and coastal maritime hammocks, longleaf pine/turkey oak habitats, grass-sedge marshes and swamp forest, cypress swamps, mesic hammocks, sandy mixed woodlands, xeric hammocks, and salt marshes, as well as wet prairies during dry periods. Western Diamondback Rattlesnake Facts At A Glance. The eastern diamondback rattlesnake is the largest venomous snake in North America. Video: Facebook/Jimmy Martin The males of some rattlesnake species, such as Western Diamondbacks, tend to fight one another when spring mating season occurs. The western diamondback rattlesnake or Texas diamond-back (Crotalus atrox) is a venomous rattlesnake species found in the southwestern United States and Mexico.It is likely responsible for the majority of snakebite fatalities in northern Mexico and the greatest number of snakebites in the U.S. No subspecies are currently recognized. Some reach 8 feet in length and weigh up to 10 pounds. Light reflected off of this snake's keeled scales makes its skin appear dull, rather than shiny. The eastern diamondback rattlesnake can be blackish-gray, olive green or muddy gray. Other Name(s): Western diamond-backed rattlesnake Scientific name: Crotalus atrox Type of Animal: Reptile Animal Family: Viperidae (the viper family) Where Found: United States and Mexico Length: 9 to 1.5 m (4 to 5 ft.)(The largest-known individual was 213 cm (7 ft.) in length). The western diamondback rattlesnake is the largest of the 32 known species of rattlesnakes found in North America, capable of growing to a length of 8.5 feet (2.6 meters).