NFTs function like cryptographic tokens, but, unlike cryptocurrencies, NFTs are not mutually interchangeable, so not fungible. In the Moonpet Legend game, the NFTs will represent the pets. There are many pets in the game, each of them has many attributes such as the three rarity types, health points (HP), speed, defense, and attack. These attributes determine the shape, color, damage and combat speed of the pets. The combination of attributes can create a nearly infinite number of pets with different idiosyncrasies, and therefore also a nearly infinite number of NFT tokens to be generated.