What was the main source for the snake design on Metallica’s The Black Album cover?

The snake design on Metallica’s The Black Album cover was derived from the Gadsden flag.

The Gadsden flag features a coiled rattlesnake and the motto “Don’t Tread on Me.” Metallica used a related snake image on the lower-right portion of the album cover, connecting the artwork to the title of the song “Don’t Tread on Me.”

The initial album packaging made both the band logo and snake extremely subtle by embossing them against a black background. That design choice led listeners and retailers to call the record The Black Album, even though its official title is simply Metallica.

The cover’s visual simplicity has produced occasional confusion about whether the album was officially titled The Black Album. It was not: the nickname describes the packaging, while Metallica is the formal album title.