Landers are a Naval Unit. They have appeared in every Advance Wars game to date. They are non-offensive Units and carry only a machine gun with emergency combat in mind, if that. They are, however, one of the few Units which can Transport other Units, as they can carry all Land Units across Sea, though they can only Load/Unload at Shoals and Seaports.
Blue Moon is one of the five main forces of Wars World. To date it has appeared in all installments except for Advance Wars: Days of Ruin/Dark Conflict. Due to the actions of Clone Andy, they are at war with Orange Star at the start of Advance Wars, though later ally with them. They are also a member of the Allied Nations.
You can download this simple papercraft template here: Advance Wars - Blue Moon Lander Free Paper Toy Download