Axie Infinity is a blockchain-based game that allows players to collect, breed, and battle with virtual creatures called Axies. It was developed by a Vietnamese studio called Sky Mavis and runs on the Ethereum network. The game has gained popularity due to its play-to-earn model, where players can earn cryptocurrency by completing various in-game tasks and battles. Axie Infinity also has its own marketplace where players can buy, sell, and trade Axies using cryptocurrency.