The cover snake on Metallica's The Black Album derives from which historical flag?

The cover snake on Metallica's The Black Album derives from the Gadsden flag.

The album cover places a coiled snake in the lower-right corner and the angled Metallica logo in the upper-left. Both emblems were embossed on the original release, making them almost disappear into the black background and inspiring the album's enduring nickname.

The Gadsden flag is an American historical flag featuring a rattlesnake and the motto “Don't Tread on Me.” That motto also appears as the title of one of the album's songs, creating a direct connection between the artwork and the track list.

The design is sometimes confused with other American flags that use stars, stripes, or historical symbols. The relevant source here is specifically the Gadsden flag and its snake emblem. Later editions changed the cover's nearly invisible embossing to dark gray artwork, but retained the same basic logo-and-snake composition.