For almost four decades animal rights activist Kim Stallwood has helped lead the best-known animal advocacy organisations in the world, including Compassion In World Farming, the British Union for the Abolition of Vivisection, and PETA. But he wasn't always a pioneer in the fight to save animals' lives, and he didn't always understand what it meant to be truthful to animal rights, or to himself. Starting in 1973, when he was working in a chicken slaughterhouse in England, to the 1980s as the first executive director of PETA, to editing the groundbreaking Animals' Agenda magazine in the 1990s, Stallwood describes his journey from clueless student to lifelong vegan activist. Along the way, he develops four key values in animal rights—compassion, truth, nonviolence, and justice—which he uses to explain how to develop one's own animal rights practice. As he does so, he shows how a deeper understanding of animal rights not only leads us to discover our humanity for animals, but also for ourselves. Equal parts personal narrative, social history, and impassioned plea, Growl is for anyone who wants to know how they can make a difference for animals, regardless of where they are starting from.