The giraffe is the tallest mammal in the world. The reach heights of nearly 6 meters. Their large eyes, long tongue, sizeable ears. Although a giraffe’s neck is 1.5 – 1.8 meters but giraffes can walk swiftly and they run swiftly, as well. They only spend between 10 minutes and two hours asleep per day. They have a life expectancy of 20-30 years. The tallest mammal in the world is giraffe.