Kau

Arbitro's beloved 'pet', who is actually a young boy. He has white hair, is covered in black leather and a blindfold, and has a large scar and piercings on his stomach (due to Arbitro's personal preferences), and walks on all fours. Because Arbitro destroyed his eyes and vocal cords, he cannot see or speak. He does, however, have a keen sense of smell, and has been trained to pick up the scent of dog tags to help find rule-breakers within Igura. His name's kanji means "dog" in Japanese. (from: Wikipedia)