Try searching for photos you are looking for at shutterstock.com
There are many good places one can look for photos of animals. There are books at the local library which have photos. An excellent source would be the internet where one can find thousands of photos of animals of every type imaginable.
Your right... there is no such thing as "rare" animals.
There are multiple online resources that one can use to find photos of animals. The official websites of the zoos are the most useful resource for the animal photos. The Australia zoo official website has awesome animal photos.
That is a complicated question seeing as it has rare,endangered animals, so a bit of both i suppose.
National Geographic has amazing photos of giant animals. Their online website has photographs that can be viewed and they have an extensive archive that can be accessed by professionals who need photos to suit a particular project.
an Eagle is an Endangered Species
The Rare animal in the wild is the Panda,even there many still there rare.
It is very difficult to find rare photos of famous people these days. However, if you are looking for photos of Serena Williams that haven't been seen by many people and don't want to pay any money for them then Getty Images might be a good place to start.
They are a rare species of animals.
It is a rare species of animals
Google it or go to a library