Most people who know me understand that I'm not a "knicky-knacky" kind of person. More things to collect dust and pack when we move (six times in the last eight years). So, when we got this house, there are all sort of built-in shelves in the living room flanking the fireplace. We had some books and a few other things. I felt compelled to get a couple extra things to "fill in." Obviously, Sam the cat felt I didn't have enough and enjoys being a mobile knick knack.
And then there's Tucker the dog who likes that corner, too. Sam will lay on the shelf and bat at Tucker just to torment him. Evil kitty!