Carved of amber-colored horn, with an ancestral face with metal inlays.

Height 11.4 cm
Width 5 cm
Thickness 3 cm
61 grams
Wood, white metal, brass, unknown black substance
Probably North Sumatra
19th century
Description
Presented is an unusual carved grip. It represents a forward-leaning figure that seems to present something with both hands. The eyes, offering, and a dot on the forehead are separate white metal inlays. The mouth is done with brass.
On top of the head is carved an opening containing an unknown black substance. It reminds of the compartment on some Batak hilts and statues that would be animated with compounds made of human tissue.1
Notes
1. Kruijt, Alb. C.; Het animisme in den Indischen archipel, Martinus Nijhoff, ‘s Gravenhage, 1906. Pages 216-220
Classification & attribution
It has been speculated that this is a keris hilt, but it doesn't resemble any known keris hilt, or sword hilt, for that matter that I am aware of.
Stylistically, it bears some similarities to Batak work, the forward-leaning posture is seen on some Batak sword hilts. The position of the arms, the opening on top of the head, and the inlaid metal eyes and mouth also all remind of Batak work. Yet, style is not typically Batak either.
See here a comparison with a Batak bullet holder, bottom, listed here.

Tentative conclusion
It was probably the grip of a betel nut crusher or other, small implement that bore enough significance to have an elaborately carved hilt. While sharing some characteristics with Batak work, it is close but not quite. It is probably from the same general area, though. I would say North Sumatra, 19th century.
It comes with a custom brass stand.











Nice and complete example with talisman basket. Probably 20th century.
Its blade with very fine and complex pamor, brought out by a polish.