I got it here: Crooked Brains, and they got it here: Gugazine (or maybe here: Doise Dois). It's by Luiza Prado, an artist in Brazil, and is called "Eatphabet."
On her page you can see closeups of the various letters, too!
It certainly does remind me of Monkey Platters, which reminds me that this fall (maybe in November, date to be announced when I know it) there will be a three day happening for unschoolers with young children in Albuquerque (local/regional, not "big conference" at all) called The Monkeyplatter Festival.
And that reminds me of the January symposium in Santa Fe called SUSS.