No. 4: Of People And Particles
While Ant-Man is the primary user of Pym Particles, there have been several other characters that have made use of them in some way in the past. If there is a superhero with the ability to change their size, the likelihood is that they make use of Pym Particles. This includes characters like Goliath (several people who have taken on this identity), Stature and even a small-time villain named Scarlet Beetle.
Despite this, however, there have been various times in which other superheroes have used Pym Particles for various different reasons. Hank McCoy and Spider-Man are two examples of such heroes. Clint Barton has made use of the Pym Particles on various occasions, mainly combining them with his trick-arrows in order to shrink down whoever was hit by them. Most surprisingly however is that Frank Castle aka The Punisher has also made use of Pym Particles. One of the incidents in which The Punisher used them involved him infiltrating an enemy stronghold by shrinking down and hiding on a Pizza, to then re-growing inside the head of one of the henchman he was targeting.
Seems about right coming from The Punisher.
