The Gadsden Flag services a rattlesnake coiled on a yellow subject with the word "Don't Tread on Me

https://blogfreely.net/dentuniphb/flagpoles-and-free-speech-why-the-stars-and-stripes-still-matter

The Gadsden Flag facets a rattlesnake coiled on a yellow area with the phrase "Don't Tread on Me." It originated in colonial America as a symbol of resistance towards British oppression throughout the American Revolution.