Gundog was a costumed, gun-wielding villain with no obvious powers who increasingly found himself dissatisfied with his career (feeling it was "no way to live"). He ultimately decided to retire in the midst of a one-day bank robbery spree when Astro City was visited by The Dancing Master.
One day, Gundog--growing bored with his life--decided to engage in a stunt where he would rob five banks in one day, just to prove to himself he could.
Among the banks that Gundog robbed was the Soglow Street branch of Carlsbank, which he hit at roughly 10:00am. An hour later, Gundog managed to temporarily incapacitate Jack-in-the-Box for several hours with a Ryman Sphere while he continued his spree. (Jack-in-the-Box would escape at roughly 4:00pm later that day.)
At 1:00pm, while at Derbyville's Kremer Street branch of Astrobank,Gundog decided to toss his weapons to a bank teller, a woman named Laura who said she was originally from Iowa (and who had been considering breaking up with her boyfriend and looking to start again, somewhere new). He asked her to keep everyone in the bank covered while he robbed other banks
At 2:00pm, Gundog returned to Laura on Kremer Street, dumped all the money he'd stolen, and absconded with his new partner. Later that evening (around 9:00pm), the pair flew off in a flying car. Gundog revealed a bit about his past to Laura, and the two decided to go visit--and potentially settle--in Maine, where Gundog's great-uncle owned a lobster restaurant.
Gundog used a number of seemingly conventional pistols, which he kept holstered all over his body. At least one of these pistols fired a Ryman sphere, which he used to trap Jack-in-the-Box during his bank robbery spree.
Gundog also drove a bright red flying car that had a 1950s aesthetic.