This fairly small, secretive relative of the cobra has black and red rings separated by yellow rings, and a black snout. Jeremiah Degenhardt/Getty Images. A narrow rusty-red line follows the spine down the length of the snake. It can be difficult with younger snakes as the difference is less noticeable with less snake to see. All rattlesnakes I have seen have black rings on the tail end just above the rattler do these show the age or something of a rattlesnake? The venomous black-tailed rattlesnake (Crotalus molossus) is a large rattler with harmful venom. Listed below is a guide to help you identify snakes by predominant color. The tail of a snake is not a venomous stinger. Many snakes vary greatly and are listed under several categories. Like all rattlesnakes, the black-tailed rattlesnake is venomous and should be left alone. Mojave Rattlesnake Some snakes, if held, will push the tip of the tail against your hand. The pupils are vertically elliptical and the dorsal scales are keeled. Common Snakes of the Phoenix Area. This species has black and white rings on its tail, so it is commonly called the “coon-tail” rattlesnake. While not all of the snakes that can be found in and around the Phoenix city limits, these are some of the most common. This species can be confused with Mojave Green Rattlesnakes.However, Diamondback Rattlesnakes have wide black bands on the tail and the upper white eyestripe connects to the corner of the mouth. Banded Rock rattlesnake (C.l. Broad black and white rings are fairly equal in width. A new section is added each time the snake sheds its skin. A single dark stripe runs back from each eye. Like all rattlesnakes, the black-tailed rattlesnake is venomous and should be left alone. The head is triangular with dark stripes running from the eyes down toward the snake’s upper lip. Home to several venomous as well as non-venomous snakes, Louisiana has been a constant attraction to snake enthusiasts who visit the area to study these reptiles. The tail is black, which is how you can differentiate it from the Western diamondback rattlesnake. The tail is black, sometimes with muted, dark, gray-brown rings. Crotalus molossus is a venomous pit viper species found in the southwestern United States and Mexico.Four subspecies are currently recognized, including the nominate subspecies described here. It can get to about 4 feet long. Unlike other large-bodied rattlesnakes in the area, they have a solid black tail area just before the rattle, as opposed to rings or stripes.