KT-4

The KT-4, also known as the Kusanagi-no-Tsurugi, is a buildable Wonder Weapon that appears in the map Zetsubou No Shima. It's capable of releasing a green liquid that makes spore bags grow on the Zombies' bodies and makes them explode. The Thrashers' spore bags will explode, making them easier to kill, whilst the Spiders instantly explode upon being affected by the weapon. For a better and more lethal shot, the player has to hold down the trigger, if done so, the liquid will stay on the floor, and affect any enemy that goes over it, much like the Sliquifier from Die Rise. It is Zombie variant of the Specialist Weapon HIVE.

In order to acquire the KT-4, the player needs to acquire three parts: After collecting all three parts, head down to the Bunker, where the player can find a table to put all three parts in. Afterwards, the KT-4 can be picked up. After the initial build, the KT-4 can be acquired from the Mystery Box by all players.
 * 1) Flower plant - In the Bunker, open the door to Mule Kick, then swim in the tunnel next to it. Swim further inside the path with blue 115 rocks all around. At the end of the path, the plant can be seen and picked up.
 * 2) Spider venom - During a Spider round, a Spider must be lured to Lab A, then lower the cage in the Lab. Lure the Spider into the cage, then raise the cage up. Press the panel next to the cage, and the spider will be extracted of its venom. The venom can then be picked up.
 * 3) Green vial - Kill a zombie with a green glow. This zombie usually spawns after round 12, and is random.

The KT-4 can be upgraded to the Masamune, a more powerful variant that has a larger chain effect. In order to upgrade, the players would need to acquire "Rainbow water" for the Bucket, seeds, the Shield and the Skull of Nan Sapwe. As with the initial build, players need three parts: After all three parts are gathered, put them on a table next to the KT-4 table, and the KT-4 will then be upgraded to the Masamune. Once one player has completed the process of upgrading the KT-4, all players in the match can upgrade it for free, by going up to the table where the upgrade was completed. However, if multiple players have the weapon in their inventory at one time, the ammo consumption of each shot increases.
 * 1) Giant Spider tooth - Use the KT-4 to gain access to the Giant Spider's lair and fight it. After killing it, approach the spider, and you can acquire one of its teeth, as well as free Widow's Wine
 * 2) 115 vial - Electrify the Shield, by completing all Trials at the Skull altar. Head to one of the Lab areas, and melee the control panel of the cage. Use the cage to lower down into an underground area, where a corpse with a 115 vial can be seen. Grab the vial.
 * 3) Plant - In the same area where the original plant can be picked up, use the Skull of Nan Sapwe to open up a secret area. Plant a seed in this area, then water it with the water three times within three rounds. Afterwards, the plant can be harvested.

Trivia

 * The full name of the weapon, Kusanagi-no-Tsurugi, is also known as the name of a legendary Japanese sword, one of the three Imperial Regalia of Japan. Its upgraded form, the Masamune, is also the name of a legendary Japanese swordsmith.