Oobleck: green slime from the mind of Dr. Seuss
Oobleck has to be one of the oddest outgrowths of literature I've ever seen, but the green slime looks like a blast to make in the kitchen.
The Instructables website says Oobleck is "a non-newtonian fluid. That is, it acts like a liquid when being poured, but like a solid when a force is acting on it. You can grab it and then it will ooze out of your hands. Make enough Oobleck and you can even walk on it!" (Or run, as in this YouTube video.)
Oobleck is named for the goo featured in Dr. Seuss' book, "Bartholomew and the Oobleck" (1949). It's a sequel of sorts to "The 500 Hats of Bartholomew Cubbins," (1938) and features King Derwin of Didd and his young subject. The King asks his magicians -- "men of groans and howls, mystic men who eat boiled owls" -- to summon something other than snow and rain from the sky, so they oblige with the green-ness that threatens to ruin his kingdom.
Not one of Dr. Seuss' most memorable books, but its impact lingers today, in kitchens around the world.