Every toad up there was drawn by Ethereum, just now.

CrypToadz live in the original contract, which records who owns each toad. Ask it what toad #1 looks like and it hands you a link to Arweave. CrypToadz Chained is a separate contract that answers the same question with the toad itself.

The chained contract isn't an NFT collection of its own. It holds no tokens and can't move one. It only implements tokenURI, the one ERC-721 function that says what a token looks like, for the same token IDs. Ownership stays where it always was.

1. + Background
   Salmon

2. + Body
   Ghost Bones

3. + Mouth
   Beard

4. + Head
   Brain

5. + Accessory II
   Short Cigarette

6. + Accessory I
   Explorer

Each frame above is a fresh call to the contract's builder with one more trait than the frame before. Here's what happens inside every one of those calls:

1. 1. Stored

   Each trait's art is kept as compact drawing instructions, compressed with DEFLATE and written into contract bytecode with SSTORE2, the cheapest place to park bytes on Ethereum.

2. 2. Inflated

   A Solidity inflate library unpacks only the traits this toad wears.

3. 3. Painted

   The traits are drawn onto a 36 × 36 pixel canvas.

4. 4. Encoded

   A GIF encoder written in Solidity turns the canvas into an image file.

5. 5. Wrapped

   Image and traits go into a base64 data: URI, which is what tokenURI returns.

The 145 toadz that weren't generated from traits, the 1/1s and the animations, are stored whole. The few toadz Gremplin touched up by hand carry small patches, so the chained copy matches the original exactly.

Every metadata file and every frame of every image was compared with the Arweave originals and the IPFS provenance images by two validators written separately: one in Node with pixelmatch, one in C# with ImageSharp.

toadz rebuilt from their traits

6,880

toadz rebuilt from their traits

1/1s and animations stored whole

145

1/1s and animations stored whole

pixels per toad, scaled up without smoothing

36 × 36

pixels per toad, scaled up without smoothing

Your toad still points at Arweave, because that's the link the original contract gives out. To point at the chain instead, a link has to name a contract rather than a server. ERC-4804 defines that kind of link, the web3:// URL, and ERC-6860 revises it.

If wallets, marketplaces and browsers resolved web3:// links, and CrypToadz metadata pointed at one, CrypToadz wouldn't depend on anything off chain: no Arweave, no IPFS, no gateway. Most apps don't support these links yet. If you build or use one, ask for it.