Cestro is the Blue Aquitar Ranger of the Aquitar Rangers, He is an Aquitian that requires waters of Aquitar in order to live, he also is the main protagonist of Mighty Morphin Alien Rangers. He is also referred to as Blue Alien Ranger on Earth, as well as Mighty Morphin Alien Blue Ranger a variation on his alternate in-show label, though it is more in reference to the show itself than a proper label.