Walka is Desert design and inextricably linked with Tjukurpa: the Law and way of life of Anangu (Central and Western Desert Aboriginal people). The symbols were traditionally used in cave, ground and body paintings, in story telling, teaching and signalling inheritance. Meaning of the designs depends on its subject and particular people are responsible for their re-creation and teaching according to the Tjukurpa. Highly experienced craftspeople have grown up making traditional tools and weapons under the instruction of their elders. They now apply this knowledge and express their world through art such as this.

Nganngi is a water-holding frog that burrows under ground during dry periods. It emerges during the rain to absorb large amounts of water, breed and feed before returning underground to hibernate. The frogs were dug up by Anangu during times of drought for a vital source of water. This walka is unusual in recounting a story more widely known across contemporary Australia. It involves a frog that drank all the available water until there was none left for anything else. The other animals, led by a wise old Owl, banded together and eventually made the frog laugh so hard the water rushed out of him to replenish the lakes, swamps and rivers.