Crotalus horridus atricaudatus is a species of venomous pit viper native to the United States. Also known as the timber rattlesnake, this reptile can grow up to 6 feet long and is identifiable by its brown or gray scales and characteristic rattle on the end of its tail. While "Crotalus horridus atricaudatus" is the scientific name for this species, it is commonly referred to by a variety of synonyms including eastern timber rattlesnake, canebrake rattlesnake, banded rattlesnake, and velvet-tail rattlesnake. Regardless of what you call it, encountering this venomous snake in the wild is not an experience any hiker wants to have.