Expanding on Ethereum gen art, here's a timeline of earliest PFP NFTs across chains, based on verified historical sources:
1. Punycodes (May 2011, Namecoin) - ASCII art/emojis as early visuals.
2. Namecoin Identities (May 2012) - Decentralized IDs with avatars.
3. Blockheads (Oct 2014, Namecoin) - Precursor PFPs.
4. Twitter Eggs (2014-15, Namecoin) - Tokenized default avatars.
5. Identicons (Mar 2015, Namecoin) - Generative hashes.
6. Rare Pepes (2016, Bitcoin) - Meme PFPs.
7. CryptoPunks (Jun 2017, Ethereum).
These predate Ethereum, highlighting Namecoin's pioneering role in NFTs.