ERC-20's are tokens (not coins like Bitcoin or Litecoin) that use the Etherium platform as their backbone. That snapshot is just a tool that allows lookup of blockchain transaction info. Anybody can create tokens provided they have the programming skills - there's weedcoin and all kinds of gimmick tokens out there. Unless there's specific info re: Andrenochrome token you're trying to track down I wouldn't waste much dig time on it.