People who are known to consistently consume goon are colloquially known in Australia as Goon Dogs. Such people often claim to actually enjoy the taste of the boxed wine, thus usually making them masters of Goon of Fortune.
The word used to scare someone. It is sometimes used when hiding from somebody and jumping out and scaring them, but it is mainly used when standing next to somebody and shouting 'Coodgybah!' to bring on the element of surprise.
Aaron: "Arhh FUCK! you scared to shit out of me"
Kerryn: "Oh my goodness!! Aaron you scared me!!!"
Ian: "Geeze don't do that to me again!!!"