I'm pleased to say that ShapeShifter has nothing to do with luring people to their doom, but it does have to do with changing appearance - namely OS X into something entirely new (not a lizard though). ShapeShifter isn't just a set of icons though - it completely changes everything from the look of menus and windows to buttons, folders and more. The idea here is to allow you to change the look of OS X as you would change your clothes, your car or anything else that we all grow bored with on a regular basis.
Once installed, ShapeShifter appears in your mac's Appearance tab, giving you a huge number of themes to choose from. You have a preview picture of what each one looks like and you can easily activate and deactivate them if you don't like them. If you want to tweak a theme to your liking, you can do this too by keeping some aspects and discarding others. You can for example, only apply a specific theme to your icons but not the rest of OS X.
Many of the themes are a bit too gaudy and weird for my tasted although some are elegant enough to grace any Mac. Fortunately, you can download more themes through the download button in ShapeShifter plus there are other sites such as resexcellence.com and interfaceLEFT.com where you can download more. The major disadvantage of ShapeShifter is that it may cause instability with individual applications that aren't familiar with the fonts, typesetting and format of different themes.
ShapeShifter is a handy application for all those that are constantly customizing the look of OS X and want more than just a pack of different icons.
Download ShapeShifter 2.5 in Softonic