Mushroom Ball

Mushroom Balls are items found in Mario & Luigi: Bowser's Inside Story and its 3DS remake during the sidequest Mushroom Ball Derby; they are balls in the form of red mushrooms. There are 16 total, each holding their own special prize if Mario and Luigi hands them to the PR Toad of Toad Town Mall. They are found around at the mall in hidden blocks and by spin drilling underground.

Rewards
There are 16 rewards, one in each Mushroom Ball. The rewards found in the Mushroom Balls are as follows (they will always be in this order, independent of the order of the Mushroom Balls):
 * 10 coins (50 coins in the remake)
 * 5 Super Mushrooms
 * 50 coins (100 coins in the remake)
 * 5 Supersyrup Jars
 * 100 coins (200 coins in the remake)
 * 5 Super Nuts
 * 300 coins
 * 5 1-Up Mushrooms
 * 500 coins
 * A Retry Clock (Treasure Specs in the remake)
 * 1000 coins
 * 5 Heart Beans (5 Heart and Defense Beans in the remake)
 * 5 Special Beans (5 Flex and Special Beans in the remake)
 * 5 Power Beans (5 Power and Speed Beans in the remake)
 * 2000 coins
 * Treasure Specs (Shield Badge in the remake)

Locations
When near a Mushroom Ball, a question mark will appear, indicating the location.

Mushroom Balls in invisible blocks:

Mushroom Balls buried in the ground: