Tombstone

Tombstones are the third creature that can be unlocked outside by upgrading the house. Once ??? are acquired they appear as three tombstones to the right of the house, and more are added later. There are six designs of the tombstones. Tombstones are required to buy more ghosts (ie. you can't buy 1000 Ghosts until you have 1050 tombstones). Once ??? tombstones and ??? ghosts are acquired ghosts come out of the tombstones.