Joja Cola

The Joja Cola is a food item that grants the Well Fed buff when consumed. It has a chance of being fished up instead of a junk item when fishing.

If this item is within a player's inventory near the Dryad, she will comment on it when the player interacts with her. If you have the item held, the player will be prompted to give the Joja Cola to the Dryad to purify it. This will trigger a sequence in which a portal will open, allowing the player to peek into the world of Stardew Valley for a few seconds. Afterwards, an item called a Stardrop will be given to the player. This item will summon the pet Junimo.

Trivia

 * This item is a reference to the item with the same name in the game Stardew Valley.