David at Ironic Sans noticed that the tiles depicting the number 42 along the 42nd Street A/C/E station wall looked almost perfect for a flip book treatment, or rather, an animated gif—he noted it looked "like consecutive frames of animation depicting a jumping or sinking number." The hypnotizing gif can be found after the jump, and for those interested in making their own, try to 59th Street station—where David notes there are similar tiles. Can you think of any others? We wish these penguins could do a little dance for us!