Chuggypig

In Cornwall in the South West of England, this is a dialect name for a woodlouse, so although not strictly slang it still owes its origins to dialect and common usage as slang words do. The difference between dialect and slang is that dialect is not constant, for example just across the Tamar in the county of Devon a woodlouse is ‘chickypig’ while in Somerset it’s ‘gramfy-coocher’ and in Gloucestershire ‘johnny-grump’.

A drinking buddy.