This is an Indian dagger carved from a single piece of (bullock) horn. There are similar examples in Oxford’s Pitt Rivers museum. One, which was collected in 1862, is referenced here:
http://objects.prm.ox.ac.uk/pages/PRMUID126301.html
Artzi suggest that they were an alternative to the typical Fakir horn daggers, which almost as often as not have metal spikes incorporated.