Sierra Leone – Orangutan Gorilla – $1 – 2010 – Brilliant Uncirculated Crown – Orangutans are the largest living arboreal animals, having longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping nests each night from branches and foliage. Their hair is typically reddish-brown, instead of the brown or black hair typical of other great apes.