As of December 2014, the rarest animals on earth are the ivory-billed woodpecker, Amur leopard, Javan rhino, numbat, northern sportive lemur, western lowland gorilla, saola, leatherback sea turtle, tiger and the Chinese giant salamander. Other critically endangered species include the mountain gorilla, northern right whale and the kakapo parrot. Overall, the rarest animals on earth tend to also be the most endangered, and this may be a difficult and ever-changing category to identify.
The ivory-billed woodpecker is so rare, no one knows if it is already extinct. In fact, it was extinct until one was spotted in 2004, although the sightings of the bird were never confirmed.
The amur leopard is the world's rarest cat. Only 40 are known to exist and they all live in the far eastern part of Russia. Their population is threatened by logging, road building and poaching.
The Javan rhinoceros live in Asia and there are only around 35 known to exist. The population of this species appears to be on the rise, however.
Leatherback sea turtles are the largest turtle species on Earth. These turtles can grow to weigh more than 2,000 pounds and grow to be more than 7 feet in diameter.
Each of these endangered species offers something unique to the world. As of the end of 2014, there are more than 5,000 animal species on the International Union for Conservation of Nature Red List of Endangered Species.