A coiled snake appears on the cover of Metallica's 1991 album and is derived from the Gadsden flag.
The album cover places Metallica's angled logo in the upper-left corner and the snake in the lower-right. On the initial release, both images were embossed and nearly the same color as the black background, making them deliberately understated rather than brightly illustrated.
The snake connects the packaging with the album's song “Don't Tread on Me.” That phrase is the motto associated with the Gadsden flag and also serves as the title of one of the album's tracks. This visual and lyrical connection is why the cover is more than a generic black design.
Later editions made the logo and snake dark gray, so they stand out more clearly. The cover has also prompted comparisons with other black rock-album covers, including Spinal Tap's fictional Smell the Glove, a joke acknowledged in Metallica's documentary.