Bomb Arrow (5e Equipment)
From D&D Wiki
Weapon (arrow), rare
This magic arrow has a packet of explosive powder strapped in a cloth bag, replacing the normal arrowhead.
As an action, you can fire one piece of this ammunition from a suitable weapon with which you are proficient. Instead of making a ranged attack roll, you shoot the arrow to any point within the weapon's short range. Any creature within 10 feet of that point must make a Dexterity saving throw with a DC equal to 8 + your proficiency bonus + your Dexterity modifier.
On a failed save the creature takes 3d6 thunder damage and 3d6 fire damage from the fiery explosion and, if it is Large or smaller, pushed 10 feet from the center point and knocked prone. On a success, the creature takes half this damage, and is neither pushed nor knocked prone.
Once this explosion occurs, the arrow itself is utterly destroyed.