How do I make an offering to the open-mouthed skull?

In RAD I somehow made an offering to the open-mouthed skull while in battle. How do I do it again, intentionally this time?


An item must be presented to the skull. Walk up to it and hold the item key to drop an item onto it to make an offering. If accepted, you will hear the Elder say “Offering Accepted” and a new item will come out the skull’s mouth. I think it is only usable once per level.