Piss artist is a begrudgingly impressed term used in
Australia for a person who is able to drink an enormous amount of
alcohol.
The term is derived from the local Aussie slang for beer ("piss") and also the copious volume of urine that a piss artist is forced to expel, often in creative ways.
You might overhear in the pub: "Jeez, mate, that Bruce is one bloody piss artist or what!?!"