These roughly human-sized reptiles have amazing feet capable of clinging tenaciously to any surface. Giant geckos are typically docile and shy but can be aggressive when cornered or defending their territory. These large-eyed lizards are found in a wide variety of habitats, from rainforests and deserts to mountain slopes or even underground caverns. They spend most of their time climbing around in large trees or on rocky cliffs, whether hunting for small animals or hiding from predators. A giant gecko's scales are often quite brightly colored or decorated in intricate patterns. Giant geckos span nearly 8 feet in length from head to tail, and they weigh about 120 pounds.