A ball fish is a very rare fish that can be obtained in the Virtual Tank. A typical ball fish costs 20,000 Shells. When they arrive in your tank, they will be a small whiffle ball, however, after about a week of constant feeding, the whiffle ball will grow into a soccer ball and eventually grow into a beach ball. Due to the beach ball's exceptional rarity and the amount of time it takes to fully raise one, they can often be considered a personal accomplishment.