Slime (Click for definition)

"Slime was a toy product manufactured by Mattel, sold in a plastic trash can and introduced in February 1976. It consisted of a non-toxic viscous, squishy and oozy green or other color material made primarily from guar gum." -Wikipedia

"A surprisingly humble cultural phenomenon, slime is a mixture of household items that come together to create a polymer substance that acts like both a solid and a liquid, depending on how you play with it." -c|net