RootBeer said: it says 'constarch'. why it's pounding on it crying, i don't know..
Corn starch and water has a very high viscosity level, which, basically means its really, really, really thick.
A slightly longer explanation is that if you push against it quickly/hard for a short time, you won't get very far. But if you push against it slowly/lightly for a long time, you'll end up sicking in. Homemade quicksand.
It's not viscosity per-se; it's a non-Newtonian fluid. It'll harden (temporarily) if it's pushed hard, but becomes more liquid under softer pressures. Google "ooblek".