Black leopard, red wolf

Series statement from Goodreads.com

"Tracker is known far and wide for his skills as a hunter: 'He has a nose,' people say. Engaged to track down a mysterious boy who disappeared three years earlier, Tracker breaks his own rule of always working alone when he finds himself part of a group that comes together to search for the boy. The band is a hodgepodge, full of unusual characters with secrets of their own, including a shape-shifting man-animal known as Leopard. As Tracker follows the boy's scent--from one ancient city to another; into dense forests and across deep rivers--he and the band are set upon by creatures intent on destroying them. As he struggles to survive, Tracker starts to wonder: Who, really, is this boy? Why has he been missing for so long? Why do so many people want to keep Tracker from finding him? And perhaps the most important questions of all: Who is telling the truth, and who is lying?"--