Raids are one of the action items on the Spinner.
When you spin a Raid, the game will transport you to another players’ Village and give you 3 shovels and 4 spots marked by an X where you can dig.
In each raid, 3 of the spots contain Coins or Chests, while the 4th is empty. The pet Foxy, which is unlocked at village 4, can help earn more coins in raids by digging up the 4th spot.
The player that you Raid is known as the Coin Master and is a friend, or random player, with the highest number of Coins.