A Neotank is the third form of a Tank in the Advance Wars series. Neotanks have a high movement and are very powerful, but cost 22,000G--the same cost it takes to deploy a Bomber. Neotanks were dropped in Advance Wars: Days of Ruin.
 Story Importance
In Advance Wars 2: Black Hole Rising, each country has an unlockable side mission that gives the country the ability to produce Neotanks upon completion. Orange Star is an exception to this rule, since its Neotank mission is unlocked automatically.
These missions have a specific Property to capture. Once this property is captured you'll unlock an Optional mission that will allow you to deploy your own Neotanks once completed.
Once unlocked in one Campaign you'll be able to use Neotanks in all other game modes.
Neotanks are very powerful, and have a high enough movement stat to make the opponent want to put priority on them. If the opponent's base has at least two paths of entry, try to defeat them by having a couple of Neotanks attack one entrance, while you have some foot units accompanied by some distance units and other tanks go from another entrance and head to the opposing HQ.