H. Porter's most notable creation is the Ray Gun. It is believed that he also invented the Wave Gun and Zap guns, but this is false. The upgraded Wave Gun/Zap Guns are simply named after him for his bravery in stealing the Nazi plans from Group 936.
But where did H. Porter come from?
He was the head of scientific studies at the US Government's hidden headquarters: Area 51. During World War Two, he was sent to Germany to work with Group 935 and Group 936. He worked with both teams and helped create the deadliest weapon of all time: the Ray Gun.
Taking all the credit, two German doctors (Maxis and Rictofen) shipped the device to reproduction, where copies of it would be made and shipped to the active German war bunkers. Then the two doctors sent Porter to work with Group 936, which is the long-forgotten group credited with inventing the very first perk machine.
While spectating this mysterious group, Porter came across blueprints for a machine which could change the particle arrangement of weapons. This machine was the Pack-a-Punch Machine, and it required excessive amounts of Element 115 to work.
But Porter remained calm and kept working on 936's current project: Stamin-Up, which was the "Speed Juice" to the Germans. Porter stole copies of the Stamin-Up blueprints and stuffed them into his pockets. Only weeks later did he escape Der Riese alive before it was overrun by the undead.
He stowed away on a Russian merchant ship, which was carrying tons of weapons from America to aid the failing Russians. On its return to America, though, it became trapped within the ice and was soon taken over by zombies. Porter's last attempts to reveal the Germans' project was successful: he stowed the blueprints in an empty crate and locked it shut. He then fled to a nearby lighthouse where he froze to death.
Years later (towards the end of the war), Russian guards went on a search party for any functional weapons still aboard the crashed ship. All ten Russians made it out alive, barely scraping the bottom of the barrel with a close zombie encounter. The mission was a huge success when they brought Stamin-Up to the light. They revealed it to all the other Allies (making sure to keep it hidden from the Axis Powers) but it was said to be a hoax.
Once a moon base was established, though, the Americans realized that Stamin-Up had been a reality. They then created a copy for themselves as well as a shipment of Mule Kick machines. The Wave Gun was also invented and credited to H. Porter, for it followed the same idea of the Ray Gun.