The slowest Reptile on earth: Tuatara
Tuatara probably have the slowest growth rate of any reptile, continuing to grow for the first 35 years of their lives. The average lifespan is about 60 years, but they can live to be well over 100 years old - one male Tuatara named Henry, living at the Southland Museum and Art Gallery, is still able to reproduce at 111 years of age. Some experts believe that captive Tuatara could live as long as 200 years.
Tuatara also have to incubate their eggs for the longest period of time of all egg-laying reptiles - they have recorded taking as long as 13 to 15 months before finally hatching!
Photo taken from here