As a child, Edward Whelan was regularly molested by his father; a wealthy and influential judge. As a protective measure, Edward would shut himself down and suppress these memories, burying deep and festering feelings of hatred, rage, shame, and loathing for his father and for himself. They lay dormant into Edward's adult years, when he became a successful geneticist.
While searching for Arnim Zola, Edward found himself in the employ of Baron Zemo, only to discover that Zemo had been transforming human beings into hideously deformed mutates. When Edward objected, he found himself becoming Zemo's newest test subject, undergoing torture and experiments which unleashed the hidden ugliness within. The years of abuse left Edward feeling so low and ashamed that he was virtually sub-human, a worthless thing, nothing more than vermin. Transformed into a rat-like creature, Vermin's intelligence was that of angry child, and he loyally served Zemo until they were both defeated by Captain America.
Fleeing into the sewers of New York City, Vermin reemerged with an army of rats at his command, but was again defeated by Captain America with the help of Spider-Man, who inadvertently triggered lifelong and severe arachnophobia within Vermin. Escaping to the sewers, Vermin cowered from Spider-Man, emerging only at night to murder and cannibalize innocent citizens. He found himself targeted by Kraven the Hunter, in disguise as Spider-Man, who defeated Vermin and held him captive as bait for the true Spider-Man, who was in a severely weakened state. Vermin defeated and nearly killed the hero, but was stopped by Kraven who released Vermin back to the sewers as a distraction for Spider-Man while Kraven committed suicide. Spider-Man defeated Vermin by tricking him to flee outside during the daytime, which confused and terrified the man-rat, whom Spider-Man then left in the care of Reed Richards.
Discovering that Vermin's mutation was more rooted in psychology than biology, Richards handed Vermin over to the care of Dr. Ashley Kafka at Ravencroft Sanitarium, the first person who was able to get through Vermin and reach the Edward Whelan within. After feeling abandoned and betrayed when Dr. Kafka took a day off, Vermin flew into a rage, killing several guard and cops in his escape. After encountering a hallucination of himself as a little boy, he took the "child" under his protection, and sought out their home to kill his/their father. He nearly succeeded, but the love he still had for his daddy kept him from acting on his hatred, and he tried to commit suicide by provoking the police outside to open fire. He was saved by Spider-Man, and returned to the care of Dr. Kafka, where he became more violent and desperate between transformations back to his original human state. He knew he was dying, and like a scared rat in a corner, that made him even more dangerous.
Major Story Arcs
Vermin was one of the many villains given the choice to join the Thunderbolts army or go to jail. Vermin chose to join the Thunderbolts, but has since been returned to custody.
Vermin was granted superhuman abilities like those of a rat through genetic engineering at the hands of Arnim Zola. His powers are proportional to those of a human sized rat.
Vermin possesses physical strength that is slightly beyond the natural physical capability of any normal human and can lift approximately 1,000 lbs.
Peak Human Speed:
Vermin can run and move faster than even the fastest Olympic level sprinter. While not superhuman, he can run as fast as it is naturally possible for a human being to run and can reach a top speed of 35 miles per hour.
Peak Human Stamina:
Vermin's musculature produces somewhat less fatigue toxins during physical acitivy than the musculature of most ordinary humans. He can physically exert himself at peak capacity for about 30 minutes before fatigue begins to impair him.
Vermin's body is somewhat harder, tougher, and more resistant to injury than the body of an ordinary human. While far from invulnerable, Vermin can endure impact forces and trauma that would severely injure or kill a normal human being with mild to moderate discomfort.
Vermin's agility, balance, and bodily coordination are heightened to levels that are beyond the natural physical limits and capabilities of even the finest human athlete.
Vermin's reflexes are similarly enhanced and are superior to those of the finest human athlete.
Superhumanly Acute Senses:
Some of Vermin's physical senses are substantially superior to those of ordinary human beings. Vermin is able to see perfectly in near-total darkness and his sense of smell is also as acute as that of a rat. He is capable of detecting the approach of other living things from well over 100 feet away, even if he can't hear or see them.
Rat Communication: Vermin can communicate with and command rats and stray dogs within a radius of two miles from him. On several occasions he has commanded hundreds of sewer rats to attack an enemy. The manner in which he commands these creatures is unknown, although it is more likely hypersonic than telepathic in nature.
Razor Sharp Teeth & Claws: Vermin possesses very sharp and strong teeth as well as 1 inch claws at the tip of each of his fingers. His teeth and nails are strong enough to gnaw through wood, fibers, and even soft metals (like lead) within minutes.
Vermin is a villain in the 2012 The Amazing Spider-Man Game. In the game, an Oscorp geneticist named Edward Whelan is accidentally transformed into the beast that is Vermin. He becomes the main source of infection in New York and battles Spider-Man. He even infects Gwen Stacy by biting her.