I recall playing with acorn meat as a kid, finding that it was a good substitute for a crayon when I wanted to color my elementary school’s walls. That lasted about one recess. Once the school found out, they made it clear that using acorns as an ad hoc pencil wasn’t high on their list of priorities.

Acorns, it turns out,  are quite edible (see this article, for example), if you’ll take the time and trouble to leach the tannins out of the meat. And recently, in the New York Times, author Debbie Lee wrote about making a Korean jelly from the lowly acorn.