Masaki's worm

Masaki's worm, also known as brain worms, are an invertebrate, parasitic species native to Nemuro. They are responsible for the affliction widely known as "jungle madness" and are behind the "Nemuro zombies". Hatching in the thousands, the worms enter their hosts orally, nasally or through the ear, eventually entering the brain cavity. From there, the worm slowly takes over brain functions, causing the host to exhibit signs of sickness including headaches and nausea.

Once the worm attains total control, the host body is used to consume food, which nourishes the worm via bloodflow to the brain, which is also slowly consumed. As more of the brain is consumed, basic brain functions are replaced by the worm itself. Eventually, the worm lays a new clutch of eggs within the host's digestive system, which aggressively leave the host body to infect more hosts. In addition to this, recent studies indicate that even corpses may also be revived by the worms, which apparently stimulate bodily activity through bioelectrical activity within themselves. Studies have proven that the worms cannot survive for long outside of a host.

Hailing from a tropical environment, Masaki's worms are vulnerable to cold temperatures. Studies of the worms have proven extremely useful in the clandestine Kairai Project, which aims to create "zombie" troops as a viable psychological weapon.