A wee holiday project, lots of fun but it did end in tears. We froze some plastic dinosaurs (we have quite a lot of them) in some water with food colouring.
Then we took a meat mallet (B made it as a kid in metalwork) and pestle (so each boy had something heavy) and smashed the ice to bits. That was the best bit. Got out a bit of aggression I think too. A couple of the dinosaurs sustained injuries which led to the tears, especially when one of the broken legs got dropped between cracks in the deck so we couldn't play dino vets.