Character Analysis
This guy doesn’t even get a name—he gets a sweater.
And when someone doesn’t have a name in literature, there’s a reason. Here, we’re pretty sure that that reason is this: the man in the red sweater is inhuman. He's a jerkosaur who beats animals. Remember, he is the one who buys Buck—he's too evil to get named.
Moreover, his name wouldn’t matter; to Buck, he’s just the man in the red sweater who carries a club:
That club was a revelation. It was his introduction to the reign of primitive law, and he met the introduction halfway. The facts of life took on a fiercer aspect; and while he faced that aspect uncowed, he faced it with all the latent cunning of his nature aroused. (1.40)
Oh, and look at that—Red Sweater Man bring Buck into contact with something else that's red: blood. Ugh: now we're seeing red.
The Man in the Red Sweater's Timeline