Slime

This has to be the easiest crafty activity- it takes minutes to make and provides hours of farty sounding enjoyment
:)

All you need is PVA glue and a saturated solution of borax- you add the borax a few drops at a time to the PVA glue until it's as slimy as you'd like!

I presented Traff with this, and he was not suitably impressed!