The Elite Twin is a boss that was added on August 17, 2018.
Elite Twin has a medium speed and health, and decent penetration. Its machine gun turret has high penetration and damage, but mostly only helps the boss to propel itself forward. Its front turrets have high penetration and damage, although some tanks still have more firepower.
Spawns by a randomizer.
Elite Twin has a medium speed and high firepower and can kill tanks with a low rate of fire easily. Tanks like Twinceptionist or Macheptionist have higher firepower, and as such can out-penetrate the boss. In order to do so, maximize bullet health and penetration, and move in a left-right pattern when fighting with the boss. This way, you can ensure Elite Twin will miss some bullets and you will be able to deal damage to it.
Another way of killing Elite Twin is finding an obstacle, be it rock or wall, picking a drone, minion, or Engineer branch tank and start circling it around the rock. While staying at the opposite side, you will deal damage to the boss while keeping a safe distance.