Raffle tickets
Tom nook raffle
Raffle Tickets are items in the Animal Crossing series that only appear in Animal Crossing and Animal Forest e+. After purchasing furniture or clothes from Tom Nook's Store, the player will receive a raffle ticket. Every five raffle tickets gives the player one 

chance at receiving a rare item at the lottery on the last day of each month.

Up to 5 raffle tickets can be stored in one spot in the player's inventory. Every month, the color of the raffle ticket changes. If there is not enough room for the raffle ticket in the players pockets, it is mailed to them. Tickets cannot be sold to Tom; he will simply refuse to buy them.