Haffenreffer Private Stock (commonly referred to as P-Stock, The Green Death, Heffy's, Haffen-Wrecker or The Golden Cap) is a brand of malt liquor first brewed in 1953 at the Haffenreffer Brewery in Jamaica Plain, Boston. In 1965, production of the brand moved to Narragansett Brewing Co. in Rhode Island and then to the Falstaff Brewing Company. It is currently brewed in Latrobe, PA and Utica, NY under license from Haffenreffer & Co. 
Known for its tagline "The malt liquor with the imported taste", it contains 5.9% alcohol by volume. Commonly found in 16 oz cans and 40 oz bottles, it is also available in six packs.
Over the years, Private Stock has been associated with both celebrities and athletes. Wilt Chamberlain promoted Private Stock with the tagline "Nobody does it bigger."
One notable aspect of Private Stock packaging is that the undersides of Private Stock bottle caps contain word or Rebus puzzles.