The Experiment From Hell
It's been a while since I showed my love of Operation White Box. Here goes.
On a remote island in 1940, scientists from Japan's infamous Unit 731, found an amazing form of life. It was neither animal, plant or fungal but took on characteristics f all three. Nourished with tree sap it would grow into a twisted copy of the tree. Nourished with blood it would grow into a twisted plant animal hybrid with a vicious temper and a cellulose-like armored skin. In short order experiments began on the locals. The Unit was spurred on by rumors of the Americans developing their own plant men (Project Cadmus).
The study was stopped after the death of 12 subjects, and the experiment was restarted using monkeys. The human subjects were hastily buried. One night locals snuck out, against the curfew and risking death, to give their friends and relatives a proper burial on sacred land.
The scientists eventually discovered the theft and Kampetai police began a brutal investigation, tracking down the burial site. To their horror, they discovered twelve twisted tree men. The creatures were immobile and firmly rooted in the ground. The scientists fenced the area off, set a guard, and then uprooted one of the tree men for testing. The locals were horrified and referred to the monsters as toponka from a local legend. A number were shot down trying to flee the Japanese occupying the island.
Feeding the creature blood from an IV the scientists waited. Over night the toponka awoke. It wrecked the lab and crushed several soldiers attempting to capture it. It roamed the island for several days before the scientists constructed a pit trap lined with a cargo netting. The toponka fell for it so to speak. A tractor then lifted the netted creature that was further restrained with netting and chains.
It proved impossible to train the toponka. Anyone sent in to try fled or died. The creature was nearly invulnerable. Pistol and rifle bullets bounced off it. In one attempt to free a trainer from its clutches, it was discovered a large knot on its chest was relatively soft. A blow to it stunned the creature. The knot was found to be a cluster of nerve and blood vessels tied directly to the beast's heart. The creature could be subdued by any blows to it and possibly killed with a bullet or knife wound to it. Unfortunately further attempts to raise toponkas were failures unless they subjects were buried in the sacred lands.
The scientists uprooted two more toponkas to send back to Japan by submarine for further examination. Eventually with the attack on Pearl Harbor the toponka were earmarked for release near sensitive Allied installations to create havoc. One was even dumped off the coast of Washington to float to shore with the tides and terrorize Seattle for a time. The creature was cornered and captured by a team of mystery men, special forces and a British Druid who pronounced it a corrupted version of the Green Man (Swamp Monsters).
Toponkas are 6 HD monsters. They strike with two gnarled fists doing 1d6 damage. If they hit a target with both fists they can grapple it for an automatic 2d6 per round until the victim makes a ST to escape. They are never surprised in a forest or other natural setting but are surprised on a 3 in 6 elsewhere. Toponkas can float. Explosions and fires do only half damage. Other weapons do a maximum of 1d2 damage. The monster will quickly regenerate damage regaining one hit point per turn. Defoliants or acids will cause 1d6 damage which do not regenerate.
Toponkas possess a thick bark-like skin. They are AAC/AC 18/2 vs. most firearms and machine-guns. Knowing of the 'heart knot' will allow shots to do full damage, however it is AAC/AC 20/0. People grappling the toponka need to hit AAC/AC 16/4 to attack the knot.
Finding the toponkas' home island and crippling the production of more toponkas became a primary objective for the Allies.