Mercer Mayer's Little Critter is having quite the grumpy day in this classic, funny, and heartwarming book. Whether he's cranky on the slide or stubborn in the sandbox, both parents and children alike will relate to this beloved story. Mercer Mayer's Little Critter is having quite the grumpy day in this classic, funny, and heartwarming book. Whether he's cranky on the slide or stubborn in the sandbox, both parents and children alike will relate to this beloved story. A perfect way to teach children about their emotions!