ooblick

/oo'blik/ [from the Dr. Seuss title "Bartholomew and the Oobleck"] n. A bizarre semi-liquid sludge made from cornstarch and water. Enjoyed among hackers who make batches during playtime at parties for its amusing and extremely non-Newtonian behavior; it pours and splatters, but resists rapid motion like a solid and will even crack when hit by a hammer. Often found near lasers.

Here is a field-tested ooblick recipe contributed by GLS:

This recipe isn't quite as non-Newtonian as a pure cornstarch ooblick, but has an appropriately slimy feel.

Some, however, insist that the notion of an ooblick recipe is far too mechanical, and that it is best to add the water in small increments so that the various mixed states the cornstarch goes through as it becomes ooblick can be grokked in fullness by many hands. For optional ingredients of this experience, see the "Ceremonial Chemicals" section of Appendix B.