Professor Smythe
Real Name: Spencer Smythe
First Appearance: Amazing Spider-Man 25, which also featured his proto-type spider-tracking robot. The first robot with the designation "Spider-Slayer" showed up in Amazing Spider-Man 58.
Died In: Amazing Spider-Man 192. Seems Smythe used radioactive power sources for his robots, but somehow didn't know prolonged exposure to radioactivity had nasty, nasty side effects. Guess he skipped shop class the day they covered appropriate shielding for radioactive power sources...
What's His Problem? As Smythe himself put it, he was a simple scientist with a simple interest -- okay, a weird and inexplicable interest -- in tracking spiders. Since J. Jonah Jameson, publisher of the Daily Bugle, always had a pretty inexplicable dislike of Spiders himself, he was the logical person for Spencer to turn to when the Professor was looking for funding. After seeing his robot, Jameson hired Spencer to track down the biggest Spider of them all, Spider-Man. Following the inevitable first defeat, Smythe lost his scientific objectivity and vowed to destroy Spider-Man. Discovering that crime paid more than science, Smythe began gathering information for criminals in exchange for a cut of their profits. He once glimpsed Spider-Man unmasked, but like Doctor Octopus before him the Professor mistakenly assumed this was some sort of trick and that the face he saw couldn't be that of Spidey. Ultimately diagnosed as terminally ill with radiation poisoning, Smythe blamed Jameson and Spider-Man equally for his condition. Determined to see the two men die together, Smythe slapped a bomb-containing pair of handcuffs on Jameson and Spidey. Alas for his final wish, he succumbed before the bomb's detonation, and Spidey had enough science savvy to incapacitate the bomb by freezing its controls.
Abilities: The professor was a genius when it came to robotics and arachnids, but a temperamental cuss when he didn't get his way. His robotic talents weren't limited to Spider-Slayers; he also constructed realistic facsimiles of the Kingpin, Sandman and the Vulture. Smythe had the smarts to go with his mechanical skills; he deduced that "ethyl chloride" could drain Spidey's spider-strength, although somehow that hasn't caught on like Kryptonite over at the Distinguished Competition.
Smythe's Spider-Slayers: The robot Smythe developed to hunt Spider-Man did so by tracing some sort of indefinable Spider-essence Spidey exudes (there's a spider-power ya probably didn't know he had). The early robots were attracted to all spiders, but tended to head toward Spider-Man because his Spider-ness so over-whelmed their sensors. The original Spider-Slayers were remote controlled, and projected the features of whom-ever was controlling them; some of the later versions had a cockpit so that the operator could directly partake in the action.
Favorite Quote: "When Jameson found me, I was an ordinary dedicated scientist -- he paid me to create the first Spider-Slayer! Time and time again I failed...until I became totally obsessed with the wall-crawler's destruction! And never once did I realize the radioactive materials I used were killing me! Jameson drove me mad in trying to slay Spider-Man...and Spider-Man turned me insane every time he survived!" (Amazing Spider-Man 190. Smythe blames Spidey and Jameson jointly for his impeding death, all the while ignoring the simple fact that he originally approached Jameson with an already-built robot. Dying a horrible, lingering death tends to warp one's mind, I suppose...)
Heroes He Kept Running Into: Smythe's arachnid expertise made Spider-Man his principal target. He also used Jameson's lycanthropic son, John (AKA Man-Wolf), to menace both the senior Jameson and Spider-Man.
People Who Think He's Not So Bad: Smythe's son Alistair took over Spencer's vendetta against Spidey, constructing the next generation of really, really big Spider-Slayers to torment our hero.
Most Despicable Act: Given the fact they can't stand each other, hooking up jolly J. Jonah Jameson to his arch enemy Spider-Man was cruel and unusual punishment. Probably the only thing that kept the two men from killing each other was knowing that they were going to be blown to bits anyway. At the end of the tense and acrimonious twenty-four hours they were forced to spend together. Spider-Man was so fed up with Jonah's company (and constant accusations) he actually swore at Jameson -- and Peter has to be pushed far to the end of his rope before he ever utters a curse. His Aunt May raised him better than that!