Monster Anemone
The biggest Anemones we've ever seen in Sydney have all been in Mosman. We're not too sure why they chose Mosman. (Not that there's anything wrong with the place - we've heard it's a lovely place to live.)
This particular Anemone was huge and was spotted living on one of the pylons in Chowder Bay. We think it is only young as it is always sucking it's fingers.
We're still trying to identify it (with help from the Australian Museum) so in the meantime we are just going to call it the Monster Anemone.