First I would not consider it junk, may cat figurine collectors out there would pay something for it. Not sure what it is made of, looks like heavy glazed pottery from here. Like someone took a mold, filled it with Terra cotta and glazed and glazed and then glazed it again. Is it solid and heavy?, or is it hollow. Personally I would place it on a shelf if you like the looks of it, if not give or sell it to a cat loving friend for a couple of dollars. Without any marking history would almost be impossible to tell. Since it was your grandfathers you can at least establish a min. age. Sorry I can't be more help. I think it is kinda cool looking anyway.