Skinks can be very hard to identify (because there are so many different ones...over 370 species), but I think they may be Southern Water Skinks (Eulamprus tympanum) according to the description in my lizard book. Here's a link to a picture from the Victorian Museum, what do you think?

http://museumvictoria.com.au/bioinformatics/lizards/images/tymplive1.htm

I haven't been to the Den of the Nargun in years, it looks gorgeous. Has anyone read the book "The Nargun and the Stars" by Patricia Wrightson? It is a children's book, but very cool.