The largest species of the genus Onychogalea, it is a solitary and nocturnal herbivorous browser that selects its food from a wide variety of grasses and succulent plant material.

The first description and a specimen of Onychogalea unguifera was presented by John Gould to the Linnean Society of London in 1840, published in its journal the following year, and assigned to the genus Macropus.

A lithograph depicting several individuals included in Gould's books of mammals, executed by the painter Henry C. Richter, was first published in the author's monograph of the kangaroo family Macropodidae.

[4] Speculation on the purpose of the horny end includes its use as a defensive weapon, delivering a blow inflicted from the very long tail, or that it is an ancestral relic of a disused function.

This form of locomotion has been attributed to variety of macropods, with contrary opinions on which actually use their large tails to pivot the hind legs forward, but video analysis of their movements confirms this species use of the unusual gait.

They occur in the northern parts of the continent, generally inland from the coastline, from the east at Cape York Peninsula, through the Top End and through the Kimberley region to the northwestern coast.

[13] The areas occupied by Onychogalea unguifera are patchily distributed within the large range, sometimes locally common or abundant at favoured sites, and this has not known to have been greatly altered since the later 20th century.

[1] The habitat occupied by O. unguifera is most often areas dominated by tussocks of tough grasses or low shrubby plant species, vegetation interspersed with occasional trees over arid landscapes, and especially associated with the meeting of clay soils at sandy loams.

The favoured habitat is not commonly found in the protected areas of the Northern Territory or Queensland, and the species is almost unknown in conservation zones in Western Australia; this may make O. unguifera vulnerable to threatening factors resulting from alterations to land use and fire regimes.

[1] Research conducted by consultation with Aboriginal people of northern Australia, who are well acquainted and with the animal and capture it for food, indicated a stable population with only a slight decline in Arnhem Land.

[16] Native predators might include Crocodylus johnstoni, a smaller crocodile that occurs in fresh water, which is known to be able to consume this larger species when dead and perhaps able to capture it when alive.