Numbakulla ('self-existing', 'come out of nothing') is the supreme creative ancestor of the Achilpa (wild-cat / native-cat) tradition recorded by Baldwin Spencer and Frank Gillen in their 1927 revision The Arunta. Arising of his own accord at the beginning of things, Numbakulla shaped the features of the country, instituted the sacred churinga, and produced the kuruna — the spirit-children that animate all living Arrernte. His story, set out in the chapter on the origin of churinga and kuruna, supplements the earlier human-origin narrative of the ungambikula, and the name shares the 'out of nothing' sense of that earlier dual creator. Mircea Eliade later took Numbakulla as a key example of a self-existing high god in his comparative work, while Sam Gill's Storytracking scrutinised how Spencer and Gillen's shifting wording across editions turned an adjective for 'self-existing' beings into a single proper-named creator.