Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae (the pit vipers). The 36 known species of rattlesnakes have between 65 and 70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to central Argentina.
Rattlesnakes are predators that live in a wide array of habitats, hunting small animals such as birds and rodents.
Most rattlesnake bites contain hemotoxic elements which damage tissue and affect the circulatory system by destroying blood cells, skin tissues and causing internal hemorrhaging. Rattlesnake venom also contains neurotoxic components which immobilize the nervous system, affecting the victim’s breathing, sometimes stopping it.
These are quite rare – I’ve not seen another full size taxidermy specimen.