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, is pushed 10 feet from the center point, and falls prone. On a success, the creature takes half this damage, and is neither pushed nor knocked prone. A Huge or larger creature automatically succeeds on this saving throw.
Once this explosion occurs, the arrow itself is utterly destroyed.