Masai Giraffe (Southern Kenya and Tanzania) The name "giraffe" comes from the Arab word "xirapha" - "the one that walks very fast". The tallest of living terrestrial animals, giraffes can run up to 35 mph (56 km/h). The Masai subspecies is known by the dark oak-leaf pattern that extends down its buff colored legs. The average gestation period for a giraffe is 457 days (long? :-).