Kangling

Kangling is the Tibetan word for a trumpet or horn made out of a human thighbone. (It may also be made out of wood or metal.) In Tantric Chöd practice the practitioner, motivated by compassion, plays the kangling to summon hungry spirits and demons so that s/he may satisfy their hunger and thereby relieve their sufferings. It is also played as a way of "cutting off of the ego."