The bottle acts as a Familiar and follows closely behind Isaac. It breaks when he receives damage, causing a blue puddle of Creep to form that will damage enemies that come in contact with it. The puddle disappears after a short period of time.
No new Creep will appear until the bottle is reformed, which is caused by entering another room.
- Holy water is water that has been blessed by a saint or clergyman. It is used to confer blessings upon believers, as well as baptism.
- The design of the item is based on the Holy Water sub-weapon from the Castlevania series of games.