Police Comics #19 (1943)

A Mr. Gridley stops to talk to Hadley, owner of some prime virgin forest. Gridley points out there must be something wrong if he's selling it for a dollar an acre, which makes Hadley break down and confess that the lumberjacks he sends into the forest never return. He's sure his rival, Ratter, is responsible. When Ratter shows up to remind Hadley of his offer for the land, the two start brawling and Gridley slips away. In the forest, he finds a group of lumberjacks being menaced by attacking ambulatory trees. Though Gridley picks up an axe and starts defending them with inhuman ability, he takes a sock to the head and his face changes, revealing to the men it's really Plastic Man. Fleeing the trees, they come upon a house surrounded by an electrified fence (Plas borrows a knife and relies on his rubbery body to insulate him when he short-circuits it), a wall of flame, and a wall of whirring saws, and helps the surviving lumberjacks over them. The house's occupant proves to be a botanist who gave the trees animal-like qualities, which is why they now walk and hunt like animals. Furthermore, he has a bear and birds in his lab that have taken on the qualities of plant life. His greatest experiment will be to do the same to humans, which he intended to do after he drops the lumberjacks through a trapdoor, and sics a tree-henchman on Plastic Man. The battle continues until the henchman attacks Plastic Man with an axe, which just bounces off and splits him in half. Meanwhile, the trees have tried to breach the scientist's defenses and caught fire, soon turning the entire forest into a blaze. Seemingly trapped, all the surviving lumberjacks confess that they're criminals, even getting Plastic Man to confess he's secretly wanted felon Eel O'Brian. The scientist, unable to cope with the loss of his life's work, dives into the flames and is instantly consumed. The others manage to escape when Woozy saves them by piloting the Goodyear Blimp overhead.