... the now famous blend of vodka, tomato juice, mashed clams and spices known as Canada's #1 cocktail. Clamato Tomato Cocktail was introduced by Mott’s in 1969 and acquired by Cadbury Beverages in 1982. With Clamato came an entirely new and unexpected juice category: seafood blends. The innovative Clamato is the #1 selling seafood blend from the frozen plains of northern Canada to the sunny shores of southern Mexico.