Ambiguously Brown: It's not entirely clear what race he is, although his mother is implied to have been black.
When asked jokingly by a fan, Gaiman has agreed that Dwayne Johnson/The Rock, who has black and Samoan heritage, would be fitting to play him, stating they are both "underestimated".
Badass: while he doesn't like to fight, he's a very big man and knows how to fight smart.
Beware the Nice Ones: Shadow's a nice guy, but he's also a very large man who knows how to handle himself. Even outside of his physical prowess, Shadow dismantles Wednesday and Loki's plans with a single awesome speech.
Big Bad: Turns out the whole war was a scam to get himself more power.
The Casanova: He charms the pants off of nearly every young woman he meets.
Consummate Liar: calls himself the best liar Shadow will ever meet. He was right.
The Chessmaster: Effortlessly plays both sides of the war against the other.
Con Man: How he goes about these days. He's done every con in the book.
Dirty Old Man: He's described as sleeping with girls who look barely legal.
Grumpy Old Man: he's often grumpy or pretending to be cheerful and reveals himself to be deeply bitter about the fact that as a god who went out of style in a land that's bad for gods, he essentially has to live off scraps.
Pet the Dog: not often, but he does occasionally get more sympathetic moments, such as when he seems to sincerely regret that he can't truly bring Laura back to life and that she had to die in the first place. He also tells Shadow, his son, that he's proud of him.
Technically a Smile: Shadow notes early on that his smile has a sinister motive just behind it, more bearing teeth than an actual display of emotion.
Thanatos Gambit: Dying was the motivation all the other Old Gods needed to band together against the new. He didn't mind because, once the battle was dedicated to him, he would get more power than he ever had before.
Cool Old Guy: Unlike veteran conman Wednesday and bitter loner Czernobog, Nancy's just fine with passing the days doing his own thing.
Sesquipedalian Loquaciousness: quite clearly loves words, something that goes with his mythical connections as a scribe, and telling the stories of people - though how true they are is in doubt, with Mr. Ibis suggesting that he does it for the love of the story.
Agent Mulder: Delivers an amazing and lengthy monologue to Shadow about all the things she believes in to get him to open up to her.
Badass Normal: Faces Mr. Town and Mr. Road, and not only does she refuse to tell them anything about Shadow, she makes fun of their names. She also hitchhikes with Shadow, who's kind of scary before you get to know him.
After drinking the water of time and a highly unpleasant process of getting rid of all the formaldehyde, maggots etc. inside her, she's back to her living self, though Loki notes that this is temporary.
Lady Macbeth: Seems Shadow's involvement in the robbery that got him in prison was her idea.
The Lost Lenore: Shadow misses her throughout the novel, and her resurrection does little to help that.
Manic Pixie Dream Girl: Deconstructed. Because of that personality, she cheated on Shadow with her best friend's husband while he was in the clink. She also puts on the MPDG act to charm Mr. Town before gruesomely killing him.