The Underground Tavern is a dark-lit tavern found underneath the Ant Kingdom Commercial District. Levi, Celia, and Vi are some of the usual customers. This is where players can take bounties which require them to find and defeat special bosses and also where they can exchange Crystal Berries for rare Medals. This is the only place Crystal Berries can be used in the game.
Carmina can be found in the Underground Tavern and introduces Spy Cards to Team Snakemouth when first talked to. After teaching them, she will leave the tavern and can be later found on Metal Island. Team Slacker will take her place at the table if all bounties have been completed.