Back when I was actively collecting Golden and Silver Age books, this one became somewhat of a holy grail. For a long time, I had owned a beautiful copy of World's Finest #123, featuring the second team-up of Bat-Mite and Mr. Mxyzptlk and I became obsessed with getting my hands on this particular issue. This was long before everything was available via reprint and it actually took me quite a while to find a nice, yet affordable copy. Was it worth the effort? I certainly think so. To see the two imps interact for the first time is a real treat. The come across as a bickering old couple, nad it's a hoot. That said, if you don't think the Silver Age can be charming, it may not be for you. The Swan penciled cover is pretty great, and Dick Sprang penciled the story itself. The real bonus here are the two back-up stories. The Green Arrow tale features the introduction of Miss Arrowette. She was always just an interesting footnote in Silver Age history but has become more important in recent years. I'm not much of a Tommy Tomorrow fan, but this particular tale is fun as he encounters his younger self. I think that all of these stories have been reprinted elsewhere, but it is still nice to have them all in one spot.