Monster on the hill

I saw this lump of concrete from a distance several times today and couldn't image what it was. As the snow begins to melt around campus all kinds of things appear - but this is in a spot I expected to be clear of foreign objects. . . my initial thought was a small gray monster. Maybe in the Troll family. It would appear as you got closer, to be a harmless lump of concrete covered with bits of moss. Maybe you would hypothesize that the snow plows turned it up and wonder how the campus will ever look nice again after a large ice storm and lots of muddy plowing. As you lean in for a close inspection it would unfold into a large and leggy troll that would quickly bash you on the head and drag you off to it's lair where you would become a delicious dinner.