Sugru is some kind of magic playdough invented by a Brit girl genius and marketed as space rubber or magic dust or something of the sort.  It can be molded and shaped into anything and can be used to repair stuff or invent stuff...

picture of Brit Girl Genius

A couple of Sugru engineers thought this was just the stuff for parts of a Gatling water gun they were thinking about.  It's hard to say what parts it was used for, but looks like a blast hosing down a few of your best pals, in color no less.  I might have to get some of this stuff...

picture of Sugru Gatling Gun

Video of gun in action