I had a couple containers of Nickelodeon Gak as a kid, as I'm sure many of you did, too. It was pretty fun until it became covered in dog hair and lint after about two minutes. But what I didn't know about Gak, is that the stuff is damn near indestrucatable. Watch this red hot ball of Nickel barely melt the stuff.
It wouldn't surprise me if one day WikiLeaks revealed that Gak was actually the byproduct of some military experiment gone awry. Seriously, what the hell were those Nickelodeon scientists up to in the 90s?