This is a 91mm Victorinox Tinker with yellow scales and the Gadsden Flag on it.
The Gadsden Flag is designed by general Christopher Gadsden in 1775 during the American Revolution. It was a motto flag for the Continental Marines. In that period the rattlesnake became an important symbol of the American colonies:
“I recollected that her eye excelled in brightness, that of any other animal, and that she has no eye-lids—She may therefore be esteemed an emblem of vigilance.—She never begins an attack, nor, when once engaged, ever surrenders: She is therefore an emblem of magnanimity and true courage.—As if anxious to prevent all pretensions of quarreling with her, the weapons with which nature has furnished her, she conceals in the roof of her mouth, so that, to those who are unacquainted with her, she appears to be a most defenseless animal; and even when those weapons are shown and extended for her defense, they appear weak and contemptible; but their wounds however small, are decisive and fatal:—Conscious of this, she never wounds till she has generously given notice, even to her enemy, and cautioned him against the danger of stepping on her.—Was I wrong, Sir, in thinking this a strong picture of the temper and conduct of America?”
– Benjamin Franklin, “The American Guesser”, Pennsylvania Journal, 27 dec. 1775.
The rattlesnake was one of the symbols used in the seal of the War Office (during the American Revolution) and its superseding offices: the US Department of War (until 1947) and the US Department of the Army (since 1947).
Because the Gadsden flag is on the front side, the Victorinox shield is moved to the backside.
external links: SAK Wiki Gadsden Flag (Wikipedia) US DoA seal (Wikipedia)