It's a funky shaped chert nodule. I used to find them in all shapes and sizes, sometimes looking like baseballs, other times like 4-5 oysters stuck together. Chert does weird stuff. Your locale says NE Ark, up by Missouri way? I did probably 100 miles on the Eleven Point, limestone seems to be a common parent rock up there, but Arkansas and Missouri have some wild rock collections. If you have tons of limestone and caves around you, then my money is on Chert. My second guess is iron infused sandstone (over time natural iron in rainwater leaches into sandstone pores and the chemistry stuff happens, electrons bond and the like and eventually the iron collects as part of the sandstone). It's a really weird rock, keep it. Your second find, the little carved figurine...IDK but in pristine condition it would have been a stunner of handiwork.
