New World vipers with hollow fangs and a heat-sensitive pit on each side of the head

New World vipers: pit vipers

loosely connected horny sections at the end of a rattlesnake's tail

shake and cause to make a rattling noise

large deadly rattlesnake with diamond-shaped markings

widely distributed in rugged ground of eastern United States

widely distributed between the Mississippi and the Rockies

small pale-colored desert rattlesnake of southwestern United States; body moves in an s-shaped curve

largest and most dangerous North American snake; of southwestern United States and Mexico

New World vipers: pit vipers

loosely connected horny sections at the end of a rattlesnake's tail