The Golden Poison Dart Frog (Phyllobates Terribilis). It is considered as one of the most toxic animals on Earth. It is a threatened, endangered species and lives in small patches of forests in Colombia.
More on the Frog: National Geographic, Animal Diversity, IUCN Red List, Tropical Rainforest Animals, Science Ray, AMNH, National Zoological Park, Wonderquest, AMNH, Facts, Wikipedia
Image: National Geographic News