Who are Billee, Joe, and Sol-leks? How are they different in nature, and how does this affect their standing in the group?

Billee is described as good-natured and friendly. He is smart and careful.

Joe is very different from his brother (Billie). He is a tough dog, who is willing to defend himself when necessary.

“Billee” and “Joe” he called them, two brothers, and true huskies both. Sons of the one mother though they were, they were as different as day and night. Billee’s one fault was his excessive good nature, while Joe was the very opposite, sour and introspective, with a perpetual snarl and a malignant eye. Buck received them in comradely fashion, Dave ignored them, while Spitz proceeded to thrash first one and then the other. Billee wagged his tail appeasingly, turned to run when he saw that appeasement was of no avail, and cried (still appeasingly) when Spitz’s sharp teeth scored his flank. But no matter how Spitz circled, Joe whirled around on his heels to face him, mane bristling, ears laid back, lips writhing and snarling, jaws clipping together as fast as he could snap, and eyes diabolically gleaming—the incarnation of belligerent fear. So terrible was his appearance that Spitz was forced to forego disciplining him; but to cover his own discomfiture he turned upon the inoffensive and wailing Billee and drove him to the confines of the camp.

Sol-leks was an experienced dog, who only had one eye. Sol-leks lives to pull the sled, and he is adept at the job. When he isn't working, Sol-leks is described as quiet and antisocial. He pulls directly in front of Buck in order to set an example.

He was called Sol-leks, which means the Angry One. Like Dave, he asked nothing, gave nothing, expected nothing; and when he marched slowly and deliberately into their midst, even Spitz left him alone. He had one peculiarity which Buck was unlucky enough to discover. He did not like to be approached on his blind side. Of this offence Buck was unwittingly guilty, and the first knowledge he had of his indiscretion was when Sol-leks whirled upon him and slashed his shoulder to the bone for three inches up and down. Forever after Buck avoided his blind side, and to the last of their comradeship had no more trouble. His only apparent ambition, like Dave’s, was to be left alone; though, as Buck was afterward to learn, each of them possessed one other and even more vital ambition.

UMUM