From a very long interview in 2011 about his career, here's an anecdote about his first art sale:
In '53, we had a mural newspaper at school. In those times we didn't know what Xerox was, we had a thing called mimeograph. And the mimeograph was messy, you had to turn this crank — so instead of using a mimeograph, we had a mural newspaper. It was in a big glass box on the wall for people to read; all the articles were there, and the cartoons that I did. The editor was a girl, one of my classmates, and she would tell me, "Sergi, sell them to magazines." To me, that was the most absurd idea — sell my cartoons. And one day she said, "We're having lunch, all of us. Sergi's inviting us." I said, "I don't have the money." She said, "Oh, yes you have. You've just sold these cartoons." She had sold three cartoons from the wall to this magazine called Ja Ja, and that was my first professional sale — in 1953. I was more surprised than anybody else.
Via.
And speaking of, the time he created a giant King Kong face:
Just read Sergio Aragonés’s account of making this King Kong face, the size of Bill Gaines’s office window out of papier-mâché, fur offcuts and porcelain eyes. This Sergio Aragonés’s Funnies series is a joy. I’m on the penultimate issue sadly pic.twitter.com/5dNQgZ2JFK
— Billy Hynes (@BillyHynes) May 26, 2021