Nato the Colonel Taurus (ナト・ザ・カーネルトーラス, Nato za Kāneru Tōrasu?), alternatively referred to as Colonel Nato (ナト大佐, Nato Taisa?), was one of the two sub-bosses that assisted Asterius the Taurus King on the 2nd Floor of Aincrad in the official service of Sword Art Online. Nato had three HP gauges. In the closed beta test, Nato was the only sub-boss, as Baran the General Taurus was the Floor Boss at the time.