A cow in a shell

I was sitting in our dining room this morning, looking out the window, watching Frankie (the sulcata) munching down on a patch of grass. After chewing the grass down to a short nub, he moved forward a few feet and began chewing on another bunch of grass. This whole picture was somewhat familiar: I had to consider that Frankie is much like a cow in a turtle shell. I grew up with quite a bit of exposure to farm animals including cows, horses, ducks, goats, chickens, etc., so the sight of an animal grazing is not all that unusual to me. I guess I could have said that 'Frankie is like a horse in a turtle shell' but the cow picture seems more accurate, and I think I remember hearing someone once saying "cow in a shell" about sulcata. So, looking out to my backyard and watching Frankie graze across his field, I admit that there are similarities between him and a cow, but at least I don't have to milk him everyday.