Scorpion

Mac is a private investigator hired by J. Jonah Jameson to follow Peter and find out the connection between Peter Parker and Spider-Man. To that end, he tails behind Peter on the street, and stakes out the Parker home. At one point, Peter (as Spider-Man) is forced to distract the private investigator with a web-bat in order to sneak into his home unseen.

After two days of unsuccessfully following Peter, Jonah taps Mac for a new scheme. Jonah brings Mac by the laboratory of Dr. Farley Stillwell - a scientist who specializes in animal mutations. At Jonah's instistance (and financial backing) Dr Stillwell applies his animal mutations to Mac Gargan turning him into a human scorpion. Dr. Stillwell's experiments give Gargan increased strength and coordination. Combining Mac's new abilities with a mechanical tail, Jonah believes that will be enough to rid the world of Spider-Man once and for all.

The Scorpion ambushes Spider-Man outside of Jonah's apartment. His super-strength is on par with Spider-Man and allows him to rip through Spider-Man's webbing like straw. The strength of his Scorpion tail gives him an extra advantage in the battle. Scorpion manages to knock Spider-Man unconscious and leaves him on the rooftop.

After two days of unsuccessfully following Peter, Jonah taps Mac for a new scheme. Jonah brings Mac by the laboratory of Dr. Farley Stillwell - a scientist who specializes in animal mutations. At Jonah's instistance (and financial backing) Dr Stillwell applies his animal mutations to Mac Gargan turning him into a human scorpion. Dr. Stillwell's experiments give Gargan increased strength and coordination. Combining Mac's new abilities with a mechanical tail, Jonah believes that will be enough to rid the world of Spider-Man once and for all. Unfortunately, Dr. Stillwell's experiments have had an unhinged the Scorpion's mind. Instead of taking instructions from Jameson, The Scorpion strikes out on his own and begins a one-man crime spree.

Dr. Stillwell catches up with the Scorpion with a serum to reverse the affects of the expirement, but instead of getting the Scorpion to take the antidote, Stillwell instead falls to death. And the Scorpion's mind has lost all concept of right or wrong.

Again, Spider-Man catches up with the Scorpion, and again the Scorpion pummels him into submission. The Scorpion strikes out after Jameson as Jameson is the only one who knows his real identity. Spider-Man hurries after in order to save Betty and Jonah.

This time Spider-Man fights smarter. He uses his agility to stay out of the Scorpion's reach and his webbing slows the Scorpion down long enough to rip the tail off his back. Webbed in a place, without his tail, and faced with Spider-Man uncanny agility, Mac Gargan proves to be no match for Spider-Man.