38 Most Terrifying Dog Breeds in the World You Must Know

12. Canaan Presa dog breed

The Perro de Presa Canario, or Canary Mastiff, was bred for herding and protecting livestock. Muscular and assured, they carry a reputation for intensity. Without proper training and socialization, they can turn aggressive and risky. With a dominant streak, the Presa Canario needs a firm, skilled handler to become a steady companion.