Quad Tank

Not to be confused with the Octo Tank, the upgraded form of the Quad Tank. The  is an upgraded form of Twin and Flank Guard. It can be upgraded further to Octo Tank.

Design
The Quad Tank has a circular base, surrounded by four cannons in a plus shape.

Technical
The Quad Tank loses the recoil but lengthens the barrel in the back and add 2 barrels, one on the left and the another on right. Or it adds three barrels. One on the back and the other 2 on the left and right. Also  it gets rid of the another barrel in front.

Strategy

 * Strong Against: Multiple enemies.
 * Weak Against: Tanks with focused fire. Has four massive gaps a tank can shoot at.

As the Quad Tank

 * Quad Tanks are great at dealing with crowds. Getting a quadriple kill has never been simpler. As you have four barrels, you can get two or more into range of your barrels and spam bullets.
 * Beware of Boosters and Tri-Angles as they can bump into your weak points and kill you quickly. To counter, it is best to have high Reload, Bullet Speed, and Bullet Damage and block your weak spots.
 * It may be better to stay as a Twin until you are able to upgrade to an Octo Tank just like the Triple Shot. Another strategy to avoid the Quad Tank is to upgrade to the Twin Flank upgrade before upgrading to an Octotank as it is the only upgrade for the Quad Tank, but it is also an upgrade for the Twin Flank.
 * Like the Octo Tank, you can spin to defend yourself and block weak points. This is helpful against ramming builds, like the Booster, Tri-Angle, Destroyer, and Fighter.
 * This tank is weak against most tanks with focused fire, like the Twin and Triple Shot, not to mention the Sniper. It is one of the tanks with the most weak points, so do your best to protect yourself, as you have four weak points where players can damage you from.

Against the Quad Tank

 * The Sniper Tree (excluding the Trapper and Overseer branch) are hard counters to the Quad Tank. They can easily pick it off due to the slow speed the Quad Tank has, and also having 4 gaps between cannons, allowing for an easy kill in all diagonal directions.
 * Body Damage builds can also take advantage of the large gaps by ramming into them. Though, try to leave your movement unpredicted by moving left and right to try and take minimal damage.

Trivia

 * Many players don't like to play as this class because of its low defense and the loss of the Twin's quick, spamming, and focused firepower. However, it is helpful in the Pentagon Nest to harvest polygons quickly.
 * It might be the most unused tank in the game.