This stuff, if you haven’t already discovered it, is wonderful for kiddies to make a mess with. Plus it’s cheap and really quick to make which is good for us! So what the oobleck is this stuff? Well, it’s goo. Goo made from cornflour, that has the weirdest consistency ever. The name comes from Dr. Seuss who wrote a book, “Bartholomew & The Oobleck” about a substance that acts like a liquid, but when you apply pressure, it turns to a solid.