As a hero who got his powers through the traumatic experience of being bitten by a radioactive spider, it makes perfect sense that Spider-Man's enemies also require wild backstories and strange powers in order to go toe-to-toe with the beloved arachnid prince.
And in this regard, Spider-Man's rogues' gallery doesn't disappoint. In fact, the various villains go above and beyond even the spookiest expectations, creating a collection of characters who could legitimately give you nightmares if you read their comics too early.
While it is slightly unnerving to have so many disturbing bad guys against one lone webswinger, it really does make Peter seem like a braver hero. After all, when you see one hero take down a man made out of bees, a zombie demon who can control centipedes, and a drug-dealing cartel of werewolves, you know he's the real deal.
Although they vary from being just gross to being downright horrific, it's always an interesting time to see these villains appear in any story - generally because they take it from being a regular superhero comic, to being a straight up horror story.
Now, while domesticated rats are generally quite sweet creatures, a wild rat still definitely triggers all the caveman fight-or-flight responses in our brain everytime we see one. Said response is decidedly more powerful when the rat is human-sized and trying to kill you, which is why Edward Whelan - also known by the slightly cruel supervillain name of Vermin - is so concerning.
Turned into a ratlike creature by Nazi scientists, Vernim would also gain the power to control other beasts, although he would largely focus on controlling other rats. This means that, were you ever unfortunate to cross paths with the man while he was enraged, you'd not only have to worry that a two hundred pound rat was chasing after you, but that tens to hundreds of other smaller rats were with him.
Just to add the proverbial horrific cherry on top, Whelan's genetic splicing also gave him a thirst for human flesh, meaning he generally uses his powers to cannibalise people in brutal fashion. At least it didn't happen to Spider-Man, we guess.