You can read more about him at his Biography.com page here, or this old Flight Club post here. But if for some reason you don’t like clicking on links here’s a brief summary:

He’s an aerospace engineer who has been involved with a number of very high-profile projects from stealth bombers to space rockets. But all of that is immaterial and insignificant to his greatest accomplishment. In the early 90s he was trying to figure out new systems for rockets and experimented with a setup he built at home. Along the way he noticed that the rig he built had certain fluidic properties, and decided to adapt his valve and pump design with a water tank attachment, and something else quite curious - a pistol-style grip with a trigger.

Yup, he invented the Super Soaker!