Impossiball was a mad rubber ball that had some kind of weight inside it which meant that however you tried to roll it or kick it it would always go around in an arc and come back to you!
The Impossiball looked like a standard, inconspicuous rubber ball until you bounced it away from you. It could do things like grafity-defying rolls and if you let it go on a hill it would even come to a complete standstill.
There was also a puzzle ball that had the same name - 'Impossiball'. However, this was a very different ball indeed. Also known as the "Incredi-ball" the Impossiball puzzle was made up of twenty different triangular pieces. Each triangle rotated around a vertex and had three different colours on each of its edge. The idea was to make sure that all of the corner colours matched to make a coloured circle. The first version of this Impossiball puzzle ball was produced by Milton Bradley - the big guns behind the Rubik's Cube.