Zarek was the former prime minister of the Kree Empire. He concocted an elaborate scheme, posing as the godlike being "Zo", in order to seize personal control of the empire. However he was thwarted by Captain Marvel and The Supreme Intelligence. The Supreme Intelligence branded Zarek a traitor of the Kree Empire and exiled him.
Zarek next emerged as a leader of a renegade band of "Blue" Kree. In Zarek's opinion, the original blue race the pure-breed of the Kree, and its rightful rulers. He set up an outpost on Earth's moon and also enlisted his Lunatic Legion to eliminate his adversary Mar-Vell. Again, Zarek and his allies were opposed and ultimately defeated by Captain Marvel.
As he particularly despises less pure bred Krees that do not have blue skin, many would consider Zarek a racist. He considers Captain Marvel an inferior and ofter refers to Kree with light skin pigmentation as "Pinks".