Knoxville Zoo is offering “Buy One, Get One Free” admission tickets during the month of December to encourage guests to discover why winter is a great time to visit. Visitors to Knoxville Zoo this time of year will see many zoo animals, including red pandas and river otters, actively enjoying the cooler weather outdoors. On days when the temperature drops below 40 degrees, some animals will be moved indoors, but visitors can still see many of their favorite animals, including elephants, gorillas, penguins, chimpanzees and reptiles, in their indoor viewing areas.