One of the earlier uses of Ethereum which is a smart contract that allows users to trade and breed kittens . Crypto Kitties became popular during the growth stage of Ethereum that allowed the growth and the use of online Ethereum gaming, users where allowed to purchase and breed kittens with Ethereum. Open sea, a crypto good store that has enabled purchase of crypto kitties, announced previously an seed equity investment worth Millions in US dollars. Crypto Kitties set the pace for NFT and crypto collectibles. As of the time of writing some crypto kitties have sold for up to $300,000.