Again, had it in a folder so long I lost the source. Any suggestions?

EDIT: Saw it credited to www.users.math.umd.edu/~wphooper/frac/frac6.gif but the link doesn’t work… so probably made by W Patrick Hooper, who did his undergrad at UMD: http://wphooper.com/

That UMD Experimental Geometry Lab has some pretty sweet math images too: http://egl.math.umd.edu/projects-archive.html