The Gibbon loves to make "creature creations." Honestly, I know he got the term from a PBS show, but I can't figure out which one for the life of me. To him, creature creation are anything animal related made with playdough.
So, when I introduced the idea of making fossils, he was more than excited.
1 cup of used coffee grounds
1/2 cup cold coffee
1/2 cup salt
1 cup flour
Plastic animals, sticks, leaves, flowers, etc to make impressions
Stir together grounds, cold coffee, flour, and salt. Knead dough for about a minute, than flatten on wax paper. Use a butter knife to cut out desired shapes, then press in objects to make impressions. Allow to dry for several days.