Which of these vodka-based cocktails is often served in a copper mug?

Moscow Mule is a cocktail made with vodka, spicy ginger beer, and lime juice, garnished with a slice or wedge of lime. It is a type of buck and therefore sometimes known as a vodka buck. The Moscow Mule is popularly served in a copper mug. Public health advisories recommend the mugs be plated with nickel or stainless steel on the inside and the lip.

Three friends were in the Chatham bar, one John A. Morgan, known as Jack, president of Cock 'n' Bull Products and owner of the Hollywood Cock 'n' Bull Restaurant; one was John G. Martin, president of G.F. Heublein Brothers Inc. of Hartford, Conn., and the third was Rudolph Kunett, president of the Pierre Smirnoff, Heublein's vodka division. As Jack Morgan tells it, "We three were quaffing a slug, nibbling an hors d'oeuvre and shoving toward inventive genius". Martin and Kunett had their minds on their vodka and wondered what would happen if a two-ounce shot joined with Morgan's ginger beer and the squeeze of a lemon. Ice was ordered, lemons procured, mugs ushered in and the concoction put together. Cups were raised, the men counted five and down went the first taste. It was good. It lifted the spirit to adventure. Four or five days later the mixture was christened the Moscow Mule.