Rusty

Rusty was an arms dealer employed by Oswald Chesterton Cobblepot, aka The Penguin, who was active during New Years Eve of Batman's second year of crimefighting.

History
Acting as one of Penguin's arms dealers, he sold various criminals some cryoguns that had been supplied by Mr. Freeze in exchange for their aid at raiding GothCorp and abducting its CEO, Ferris Boyle, ensuring a crime wave involving freezing people developed in Gotham. After Batman failed to apprehend Mr. Freeze or prevent his abduction of Ferris Boyle, the Caped Crusader tracked down Rusty in order to locate Freeze, based on what one of the criminals stated after being interrogated by him. Meanwhile, a cop proceeded to stumble upon Rusty and tried to apprehend him in the Diamond District alongside Rusty's goons. However, he ended up freezing the cop easily due to his being ill-equipped to deal with the cryogun's cryogenics-based ammunition. He then left to make a sale, also having his men keep guard, though he was unaware that his cryogun was leaking. Batman later uncovered both the frozen guard and the leak trail, tracking him down to another area of South Gotham just as he was about to make a sale to some crooks, who were more curious as to how it freezes people than how to shoot it. After subduing them, he then interrogated Rusty, demanding to know where Freeze was. He then revealed he was headed to GothCorp, also revealing GothCorp's access codes as proof when Batman did not believe his claim due to GothCorp not developing weaponry, let alone cryogenic-based weaponry. His words would eventually prove true and also be the first set of evidence of what really happened that caused Mr. Freeze's origins.

Powers and Abilities
He was an arms-dealer, and was also shown to be a good shot, as evidenced by his quickly freezing a cop despite being caught by surprise.

Trivia

 * Rusty's name wasn't given in either Batman's crime scene analysis of the frozen cop or his encounter with the arm's dealer, although he was identified as such by the criminals in the area the frozen cop was found, where they referenced the cop being frozen by him.