online source: Library of Congress
You can also see a hand-colored version from 1477 at the University of Munich Digital Library, and also a black-and-white version from 1479. The Spanish artist is clearly following the earlier Steinhowel tradition, but with some lovely innovations of their own!
The way I'm going to use this illustrated Aesop is to accompany texts from Caxton's Aesop of 1484, along with my own modernization of Caxton's text. I think this will be a fun way to introduce people to Caxton's Aesop, while also bringing the beautiful images from this book into play. You can find Caxton's text in the Joseph Jacobs edition at the Internet Archive; the modernizations are my own. To keep the entries brief, I am focusing just on the story, leaving out the promythium and epimythium (i.e. the "morals of the stories"), but you can find all of that in Jacobs' book.
Meanwhile, if you want to read the Renaissance Spanish text, just check out the Library of Congress online edition of the book!
These are the fable illustrations I have used from this book, accompanying the fable from Caxton's Aesop: