Although it has not been conclusively proven, it is believed that the giraffe has a black tongue in order to protect the tongue from the sun because it spends a large part of their day reaching out with its tongue for food, as noted by Smithsonian. Without this dark color, it is believed that the giraffe's tongue might become sunburned.
Other animals, such as elephants, are also prone to sunburns. Elephants will put sand over their backs in order to protect themselves from the sun. Fortunately, most animals have developed adaptations that protect them from the sun or that prevent sun burns. A giraffe's tongue is approximately 18 to 21 inches in length, and it is the best way for the animal to gather food from tall trees and plants. The tongue, while black towards the end, is often pink or purple towards the top.
Giraffes are the tallest mammals in the world, measuring as tall as 14 to 19 feet when including their long necks. They are herbivores and spend their time in open grasslands. Giraffes will eat several hundred pounds of plant leaves every week. However, they do not need to drink as often as they eat and only need to drink approximately one to two times each week. Giraffes, when drinking, have to bend down in a way that makes it difficult for them to observe their surroundings due to their extreme height. This means that predators are better able to attack while the giraffe drinks.