The muse behind comedy writer Tom Cohen's book is not just furry and adorable. "My dog Piper inspired me to write the book. She's a cross between a shih tzu and a lhasa apso, and has an old lady face," Cohen tells PEOPLE. "Since I'm a comedy writer, it made sense to write some captions to go along with their amazing faces." Behold, our favorite shots from Dogs with Old Man Faces: Portraits of Crotchety Canines, a book filled with pictures of canine curmudgeons.