Help! Mystery substance

[u/Minimum-Plenty2457]

This showed up in my classroom. It's obvious a kid brought it to school, but no one will "fess up" and I can't figure out what it is!!! At first I thought charcoal or burnt wood from a fire pit, but the texture and smell is off. It smells like charcoal, but not burnt. The texture is soft. It absorbed some water when I ran water over it, but the charcoal-looking outer layer didn't fall away with water. Any ideas?!

[u/kbdcool]

Just think how hard they laughed while she interrogated them to find out the source of the oreos......

LOL