Baskets are used for raising Fantastic Pets. You can use them after you become a Lounge member.

When you become a Lounge member, the icon of Lounge will be replaced by Fantastic Pets.

Now you can use your Baskets to level up pets.  When any pet reaches Level 4, they can create a gift every 24 hours. When all of your pets reach highest level, you can unlock Fantastic Pet Home Construction. The top 50 players in rank will receive big prize every week.