A dense claylike ball, tightly wrapped  fabric inscribed with runic lettering. As an action a character can throw throw the ball up to 60 feet away.

Each creature within 20 feet of the ball must make a DC 15 Dexterity saving throw, taking 5d6 thunder damage on a failed save, or half as much damage on a successful one.

Notes: To arm speak the phrase " Garf Ni'So ". Once armed it can not be disarmed and will detonate at the end of your turn.