Toxin tractor

The Toxin Tractor demonstrated how the GLA made use of anything and everything to hand. Toxin Tractors, as their name suggests, were ordinary civilian tractors refitted with crude armour plating and, more importantly, multiple tanks of toxin and a toxin-spraying turret. Toxin Tractors were capable of clearing buildings garrisoned by the enemy. When stationary, Toxin Tractors could be ordered to contaminate the area around them.

Upgrades

 * Anthrax Beta - Improved the toxin used by the Toxin Tractor. Available from the Palace. (Note that Dr. Thrax could upgrade to Anthrax Gamma instead).
 * Junk Repair

In addition, the Toxin Tractor could be improved to a limited degree with salvaged parts from destroyed enemies.

Tactics/Counters
Most of the time GLA generals used the Toxin Tractor only as an easy way to clear garissoned buildings, mainly because it was so ponderously slow. It was also lightly armoured, although it was known to have a surprising resilience against RPGs. The Toxin Tractor was also deadly against infantry in direct confrontation. However, against the majority of enemy vehicles, the Toxin Tractor was of little use, although Dr. Thrax's Anthrax Gamma allowed it do deal a surprising amount of damage. Toxins were also useless against buildings, and the Toxin Tractor required protection from aircraft.