After looking at hundreds of comic book covers, it becomes quickly apparent that not every cover is 100% original. Whether done intentionally or even underhandedly, there's something about uncovering these "swipes" that adds a new element of fun to reading and collecting comics. You'd be hard-pressed to find a better Hulk writer than Peter David. His decade-long run redefined the Hulk for a whole new generation, running from 1987 to 1998. Midway through this magnificent feat, David paired with another well-regarded comics creator, George Perez, to produce a two-issue mini-series pitting the current Hulk (in his Professor Hulk state of being) against the Maestro (a future version of the Hulk who has taken control of the world - and not in a good way). The only hope the future has against the Hulk is ... the Hulk! Marvel celebrated this mini-series (who's significance was felt longer after its release) by publishing the story in a prestige format with embossed covers. Playing off of the duality of the two main characters, Perez used a reverse-swipe method for the cover art. (I've got the second image flipping horizontally so you can see how close the images actually line up)
the Incredible Hulk: Future Imperfect December 1992 George Perez the Incredible Hulk: Future Imperfect January 1993 George Perez
On Ebay: Hulk | Future Imperfect | George Perez | Peter David