CryptoPunks
CryptoPunks are 10,000 unique collectible characters with proof of ownership stored on the Ethereum blockchain. No two are exactly alike, and each one of them can be officially owned by a single person on the Ethereum blockchain.
The CryptoPunks are 24x24 pixel art images, generated algorithmically. Most are punky-looking guys and girls, but there are a few rarer types mixed in: Apes, Zombies and even the odd Alien. Every punk has their own profile page that shows their attributes as well as their ownership/for-sale status.