Pig and Whistle
The bowl and wassail, or the wassail-cup and wassail. A piggen is a pail, especially a milk-pail; and a pig is a small bowl, cup, or mug, making “milk and wassail;” similar to the modern sign of Jug and Glass- i.e. beer and wine. Thus a crockery-dealer is called a pig-wife.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894