Best definition
You ripper!
Australian (informal; colloquialism)- A light-hearted phrase used to express encouragement and rowdy approval towards another, often acknowledgement of a difficult

accomplishment. Considered a “trademark” of the Australian jargon (the latter aptly known as “Strine”, after the supposed initial pronounciation of Australian language)

Average Joe #1: Did ya hear? Melbourne hammered the Swans by a bloody 50 points in last nights game at the MCG! Our team’s gonna make it to the finals!

Average Joe #2: Really?! You ripper!