Where is irony when Lip-lip is the cub’s own kind, but....

Lip-Lip is his own kind, but he attacks him anyway.... the fight is not puppy play.

Lip-lip was White Fang’s own kind, and, being only a puppy, did not seem dangerous; so White Fang prepared to meet him in a friendly spirit. But when the strangers walk became stiff-legged and his lips lifted clear of his teeth, White Fang stiffened too, and answered with lifted lips. They half circled about each other, tentatively, snarling and bristling. This lasted several minutes, and White Fang was beginning to enjoy it, as a sort of game. But suddenly, with remarkable swiftness, Lip-lip leaped in, delivering a slashing snap, and leaped away again. The snap had taken effect on the shoulder that had been hurt by the lynx and that was still sore deep down near the bone. The surprise and hurt of it brought a yelp out of White Fang; but the next moment, in a rush of anger, he was upon Lip-lip and snapping viciously.