Ethnographica - Carved wooden skull hook / hanger or 'Agiba', Kerewa people, Goribari Island, Papuan Gulf, Papua New Guinea, incised hardwood and natural red pigments, 82cm high

For another agiba, see https://www.metmuseum.org/art/collection/search/311237 where stated:

Headhunting was an integral element of religious practices throughout the Papuan Gulf, honouring the spirits (imunu) whose powers sustained the community. Kerewa men formerly lived in communal men-only houses divided into cubicles in which the members of each
clan or subclan slept. Each cubicle housed a clan shrine containing one or more agiba and other sacred objects.

The agiba symbolized the vitality and martial prowess of the clan, presiding over the skulls obtained by its members.
The skulls were hung from the agiba by loops of rattan placed over the hook-like projections at the base. At times,
a platform was constructed below the image to support the weight of the assembled skulls. Only men who had captured
an enemy head were entitled to carve agiba.