4Dogs -- and cats, and hamsters, and even monkeys and tigers -- are our best friends. And so, with the sixth book in the phenomenally successful 'Life Picture Puzzle' book series, we offer a menagerie of animal puzzles -- 176 pages of them -- that will challenge even as they delight. Animal pictures are always the cutest and most heartwarming, and when you play with those pictures (an extra whisker here on Puss, one fewer fish in a school of Nemos, a longer or shorter neck on Mr. Giraffe), the 'awww' factor is off the charts. This book will appeal not only to our dedicated Puzzle fans, but to animal lovers of every stripe (or pattern of spots). By focusing on Animals, LIFE's editors are producing the most smile-inducing Picture Puzzle book yet. Once again, the puzzle in these themed books will be organized according to level of difficulty: novice, master, expert, and genius, with a suggested completion time included for serious puzzlers.