Pigasus, the flying pig, was used by John Steinbeck throughout his life as a symbol
of himself, "earthbound but aspiring."
Below is Elaine Steinbeck's explanation of the origins of Steinbeck's trademark symbol:
The Pigasus symbol came from my husband’s fertile, joyful, and often wild imagination. After his signature on letters or inside his books, he would draw a fat little pig with wings, and lettered his name, “Pigasus.” John would never have been so vain or presumptuous as to use the winged horse as his symbol; the little pig said that man must try to attain the heavens even though his equipment be meager. Man must aspire though he be earth-bound.
At some point, he began to write “Pigasus” in Greek letters, and he added the motto, “Ad Astra Per Alia Porci,” “to the stars on the wings of a pig.”
Once in the ‘50s when we were living in Florence, we became friends with a Florentine nobleman and his family. Count Fossi was a delightful old gentleman, a student of the Arts, and his avocation was drawing. He proposed to John that he should draw a proper Pigasus, and he asked, “Should I draw it in the style of Michaelangelo or Rafaello?” John chose the latter. And here is the result.
—Elaine Steinbeck, who inherited the stamp (March 1983)