Ka-Zar's father discovered the Savage Land years before he took his young son to visit. He was then killed by the Man-Apes. Kevin was rescued by a sabertoothed tiger called Zabu, who became his closest companion and protector. Kevin grew up in this isolated seclusion and was called Ka-Zar, which means "son of the tiger." He is also referred to as Lord of the Savage Land, drawing upon both his lineage and his remarkeable resemblance to a blonde Tarzan, but he lays no claims to actually ruling it.

When Magneto took control of the Savage Land, he mutated many of its inhabitants. They then fought the X-Men whenever they went to the land, and Ka-Zar as well.

Upon first meeting the X-Men, Ka-Zar had forgotten most of his English and wa anything but civilized. But, he regained his knowledge and has since become an ally to the X-Men. He married a zoologist from New York and has a son, Matthew.