The Gadsden flag is a historical American flag with a yellow field depicting a timber rattlesnake coiled and ready to strike. Beneath the rattlesnake are the words "DONT TREAD ON ME". Some modern versions of the flag include an apostrophe.

The timber rattlesnake, canebrake rattlesnake, or banded rattlesnake is a species of pit viper endemic to eastern North America. Like all other pit vipers, it is venomous, with a very toxic bite. C. horridus is the only rattlesnake species in most of the populous Northeastern United States and is second only to its relatives to the west, the prairie rattlesnake, as the most northerly distributed venomous snake in North America. No subspecies are currently recognized.