I always get nervous when the Sunday funnies are rearranged. That's because it only happens when there's a change in the lineup. Apparently editors believe that readers won't notice a strip's been added (or deleted) if most strips are in a new location.
I had that sense of unease recently when I ran across Zits in a new location. Then, as I read it, I realized that it wasn't the signal of a comics lineup change. Rather, it was an excellent joke by Pearls Before Swine creator Stephen Pastis -- and I completely fell for it. (click on image to enlarge)
Pastis so perfectly captured Jim Borgman's style that I really thought I was reading Zits -- at least for the first panel.
Crossovers between comics can be entertaining, but only if the art works. If the characters are too far removed from their original look, then the reader has to work harder to process what he's seeing, and the humor get lost. Not so with Pastis. This was a masterpiece.