A fifty-foot, metal-eating robot. It fell from space, so its creator(s) is presumed to be extraterrestrial. It arrives on Earth slightly damaged and with no recollection of its function. Judging by the capabilities it shows later on, it was designed as a vanguard unit for planetary invasions... although it's not clear if Earth was its original intended target. Unaware of its own function when it arrives, it eventually encounters and befriends Hogarth.
The Smurfette Principle: The only noticeable female in the movie. Subtly lampshaded in a deleted scene where Hogarth shows her some of his comics books, and she points out the lack of female characters.
Widow Woman: Her husband is implied to have died during the Korean War.
Dean Mc Coppin
Played By: Harry Connick, Jr.
A beatnik artist and junkyard owner who "sees art where others see junk".
Badass Pacifist: Dean is portrayed as a man of action, but not of violence (tying into one of the movie's themes.) Culminates with him convincing the military task force that the best way to keep America safe is to not attack the Alien Menace that's currently blowing things up.
Beatnik: Complete with a job as an artist, and love of espresso.
Properly Paranoid: We all know he's right about there being a giant metal man. He even turns out to be right about it being very dangerous... to its enemies. His superiors simply think he's wacko.
Reassigned to Antarctica: What Rogard threatens him with after Dean and Hogarth's ingenious plan succeeds. It's also a popular interpretation of his status at the beginning of the movie, given his high-and-mighty attitude in spite of clearly being in a dead-end government position that nobody takes seriously.
Screw This, I'm Outta Here!: When he launches the nuke and realizes it can't be stopped, he grabs a jeep and runs about 3 feet before the Giant stops him.
Well-Intentioned Extremist: He's trying to ensure his country's safety... he's just not very good at handling unknowns. Or evaluating threats. Or pursuing investigations. Or outsmarting small boys.
Played By: John Mahoney
The Army (National Guard?) leader in Washington, D.C. who is the military liaison with Mansley's department. He doesn't like Mansley or feel that this 'giant metal man' thing is anything but a hoax. Once he knows the threat is real, he responds bravely and efficiently - though it soon becomes clear that his unit is up against something too hot to handle.
Face Death with Dignity: Despite facing an imminent nuke strike thanks to Mansley, Rogard remains dignified the entire time and calmly informs him that there is no way to escape their fate. Luckily, the Giant saves them.
Four-Star Badass: The guy's reaction to a pissed off, gun packing giant is to whip his pistol out and shoot at it.
Hollywood Tactics: Mostly subverted. He brought infantry, a few tanks, and the ability to call in air support, Navy artillery - or even a nuclear strike. Given that a substantial threat appeared 'out of nowhere' right in the middle of a civilian population, the military response seems pretty well-planned. A purist might point out that the tanks shouldn't have been sent up close.
Reasonable Authority Figure: He knows the Giant is a possible threat, but he doesn't use force until it seems necessary. After it becomes apparent that Mansley lied about the giant killing Hogarth, as well as Dean explaining that the Giant only reacts defensively, he immediately calls off the attack and orders them to stand down.