5) Kangaroo I
Sometimes a person experiences an event so traumatic, it causes them to become fixated on it, using it as motivation to shape body, mind and soul into a weapon. Other times, a person just likes kangaroos too much. Such was the case with Frank Oliver, whose marsupial fixation led him to jump and box like a kangaroo through "practice, diet and determination". Frank shared one other trait with his namesake - he had about as much brains, and was turned to ashes when he attempted to steal a radioactive isotope despite repeated warnings from the webhead.
When you think of every weapon ever invented, the boomerang doesn't exactly spring to mind as the most dangerous. It probably wouldn't even be in your top 100. Certainly there are several types of Mongolian battle spoons and a particularly malevolent strain of custard that would edge it out. This didn't deter Australian immigrant-turned-baseball player-turned-bribe-taker-turned-assassin-for-hire Fred Myers (in what must be one of the most stunningly nonsensical character backstory's in the history of everything) from choosing it as the inspiration for his criminal persona. So, in between throwing boomerangs, he gets regularly beaten up by Spidey and has jet boots because I HAVE NO IDEA.
Shot by the police, Richard Deacon agreed to undergo an experiment that would save his life and was imprinted with the genetic coding of a fly. Not even a really exotic, venomous, barb-shooting one from the darkest recesses of the Brazilian rainforest; just a totally normal, common housefly. Seriously, out of every single insect that ever came into your house, can you think of even one that is less intimidating? As well as superhuman strength, speed and endurance, the Fly also had the power to sit on your food, buzz around your head annoyingly, be attracted to poo and die in your soup. Known weaknesses include: bug spray, fly swatters, soup (see above).
2) Big Wheel
Jackson Weele was a crooked businessman who, seeking revenge on Rocket Racer... no, you know what? Screw it. It's not worth it. His "power" is to ride a high-tech, armored unicycle. With arms. That can climb up buildings. FOR SOME REASON. Big Wheel's dazzlingly short criminal career came to an end when he drove himself into the Hudson River at the end of his first "battle" with Spider-Man and was presumed (but unfortunately wasn't) dead.
Gordon Thomas, a.k.a. Typeface is easily the worst supervillain to have ever defeated Spider-Man (yes, he went on to become a horrible antihero later, but that's another list entirely). What are his super powers, you ask? He has none. He just throws a bunch of razor-sharp and explosive giant letters at people. It's like he spent years researching the most impractical, unwieldy, unintimidating, un-aerodynamic projectiles on earth and then went with them anyway just for the hell of it. Aside from that, Typeface is actually a pretty cool villain. Except for, you know, his atrocious name, ridiculous costume and, well, everything. Thankfully he died during the "Civil War" event, so he can't hurt us anymore.