Lallagullis were pixies in the Australian Brownie Guide mythology and this was a common name for Sixes.
"Lalagullis are graceful, laughing water nymphs who help the streams and lakes to keep all things clean and bright. They see that the water-lilies and other water plants are refreshed with the clear, cool water. Their particular delight is to watch over the sleek, shiny platypus babies as they tumble and play in the sparkling waterways." (The Australian Brownie Guide Handbook, 1975)