Giraffa camelopardalis .. the tallest of all land animals.
It is said that giraffes evolved a long neck in order to feed off the top of trees, avoiding competition with other browsing mammals. However, most leaves are actually eaten by insects who can get to these leaves as well as any other. Personally, I think the long neck is an adaptation to having very long legs. The long neck allows the giraffe to reach water without having to get too far down on the ground or lay on its side.