Behold, Doctor Elrod Purvis, a biochemical researcher transformed by greed (and Viper Mutagen 368) into the hideous Dr. Viper. Half snake, half kat, no soul. Killed by the terrible process of his transformation, when he returned to the living he brought with him a fearsome insanity, and a desire to transform the world into a poison swampland. Driven by the strength and conviction that only madness can hold, he sought revenge on the kat he blamed for his "accident" - Dr. Zyme. Dr. Viper's thirst for vengeance and power was not slaked by Zyme's death, and the serpentine supervillain turned his attentions to Megakat City. Believing that his form was a higher form, and that kats were inferior, he constantly experiments to create life from nature. Playing God, he creates Plantimals- mutated animals and plants that mindlessly serve only their master, Dr. Viper. Horrible and deadly, an atrocity of nature, they are dispatched to battle civilization. It is the classical battle of Kat vs. Nature, only far more fatal. A war in which the loser must turn his humanity over to Dr. Viper, and wallow in the mire of Megaswamp City- animals like all the rest, until the end of time.