Explosive Ammo

Fire this with the slingshot.
Overview
Explosive Ammo is a one-time use ammunition item for the 
It has a blast radius of 2 tiles, making it a useful option for hitting clustered enemies or breaking multiple targets at once. Explosive Ammo detonates when it strikes an enemy, a cave wall, a ladder, or water. If it does not hit one of these valid targets, it passes through objects such as rocks or plants without exploding. Because of this, its behavior is more selective than ordinary ammunition, and positioning matters when using it in combat or in mines.
A few practical points:
- It is equipped by selecting the ammo, then using it on the Slingshot.
- It is consumed on use, so each shot costs one piece of ammo.
- Its explosion can affect nearby enemies even when the direct impact is not ideal.
- Since it detonates on walls and ladders, it can be useful for triggering explosions in tight cave spaces.
Explosive Ammo also has a dyeing use. It serves as a red dye in the dye pots in 

Official description
Fire this with the slingshot.