Super Mario Bros. glitch: The determined Koopa

I've seen lots of glitches in Super Mario Bros., but this one was new for me. It was caused by my leaping over the "top" of the screen as the turtle shell dropped off the bottom edge; it registered as me stomping the shell, causing the shell to come to a stop. After a few seconds, the turtle reemerged from the shell and continued walking along the bottom edge. Video games! 30 years later, they still do weird and unexpected things.