Doggy is a rather difficult to read font-family rendering words as dogs through the OpenType ligature feature. Depending on the length of a word the dog respectively gets longer or shorter. One letter words result in a sitting dog. After the great success of the initial Dachshund style it was bred into a family of four styles with the fonts Chihuahua, Poodle and Duck. Some mutant heads are accessible through Stylistic Set features. You need a layout engine that is able to process OpenType features to make use of the fonts!