Who paid Mac Gargan to become the Scorpion?

The correct answer to this question is J. Jonah Jameson. He is a fictional character, created by Steve Ditko and Stan Lee. J. Jonah Jameson appears in the Marvel comics, making his first appearance in 1963 in the comic The Amazing Spider-Man #1.

He is the editor in chief of the fictional newspaper the Daily Bugle. J. Jonah Jameson is apart of many teams including the aforementioned newspaper and other publications such as Now Magazine and Women Magazine. He hired Mac Gargan to become the Scorpion in the hopes to find out how Peter Parker took photos of Spiderman.