A beautiful black-and-white Great Dane named Penny is one of the dogs that play in the park near my house. Penny is smart, well-trained and amazingly graceful for a creature the size of a Shetland pony. I'm amazed at how nimbly she plays with smaller dogs and confounded by how much space and food she must require. Penny's owners wouldn't trade her for a gold-plated Yorkie, though. She's just right for them.