A relic from yesteryear

I think I got this in my change from shopping recently. Didn't realise what it was until I tried to spend it and was told by a very young assistant that it wasn't 'real' money. Well, it's not, but I was glad she pointed this out because it is now one of my 'treasures'. I was fascinated by the rampant kangaroo with what I think is a lion's tail. Some research is required, I think. Australia went metric in 1968 so this has been obsolete for a very long time. It's quite amazing that it is still circulating, and that it is 60 years old!