What is the most rear animal in world?

There's no such thing as a "most rear" animal! It sounds like you might be looking for a word like:

* Rarest: This refers to an animal that is very uncommon and has a small population.

* Rear: This refers to the back part of an animal's body.

If you're trying to figure out which animal is the rarest, that's a question that's hard to answer definitively. The populations of many animals are constantly changing, and new species are being discovered all the time.

Could you tell me more about what you are looking for? I might be able to help you find the information you need!