Crazy Bones were a childrens toy sold in the US by the same guy that did Pogs. They were small hard plastic figures, solid colors, sometimes translucent, very rarely painted with one or two other colors.
They were used for playing a game. I think the game originally involved ... Throwing them at the ground and counting which direction they were facing for points.
There was a gambling aspect to it, too?
But mostly we used them like jacks, or we'd line them up and try to knock them over.