The Flat-Coated Retriever’s eponymous flat-lying coat comes in lustrous black or liver, with feathering at the legs and tail. A distinctive breed hallmark is the long head—unique among retrievers—which projects a smart and kindly expression. A Flat-Coat will stand as tall as a Labrador Retriever, but in silhouette they present a leaner, more elegant look. Dogdom’s champion tail-waggers, Flat-Coats are among the happiest of all breeds. They mature slowly; some owners say that they never grow up at all, retaining a puppyish taste for rambunctious mischief into old age. This can be either delightful or exasperating, depending on your tolerance for such monkeyshines. This highly energetic breed requires lots of outdoorsy exercise (akc.org).