Karnak is the second son of an Inhuman priest / philosopher named Mander and an ocean biologist named Azur.

They sent their first son, Triton, into the Terrigen Mist when he was an infant, rendering him incapable of functioning outside an aquatic environment. Thus, they pleaded to raise Karnak without Terrgen mutation (Terrigenesis). Karnak was enrolled in his father's religious seminary in the Tower of Wisdom, where he trained in various physical and mental disciplines until he was eighteen years old. Azur died in a mysterious undersea mishap. Mander is still a teacher at the seminary.