Agkistrodon is a genus of venomous pit vipers commonly known as American moccasins. The genus is endemic to North America, ranging from the Southern United States to northern Costa Rica. Eight species are currently recognized, all of them monotypic and closely related. Common names include: cottonmouths, copperheads, and cantils.
Agkistrodon bilineatus showing the large symmetrical platelike scales on the crown of the head that are characteristic of all species in the genus. The hazy blue eyes are typical of snakes that will soon shed their skin.