published by DC Comics
. General Zod first appeared in Adventure Comics #283
General Zod was originally portrayed in the comics as a native of Superman's home planet of Krypton who, due to the heinous nature of his crimes, was sentenced to be banished into the Phantom Zone. The Phantom Zone allowed those who were in it to see our reality but not interact with it. After the destruction of Krypton, those who were trapped in the Phantom Zone believed that they were trapped forever, an endless insubstantial existence. It was not until Superman learned how to open up the Phantom Zone that they were able to escape. When those trapped there discovered that Superman was the son of the man who had found the Phantom Zone, they would often seek to use their new found abilities to exact their revenge on Jor-El's off-spring.
General Zod clashed with Superman on a number of ocassions. He was portrayed as a bald man and was often portrayed as a Kryptonian version of a Nazi. But with his ingrained hatred for Jor-El's family, his military training, and the powers he possessed as a Kryptonian under a yellow sun, General Zod was always a tough opponent for the Man of Steel.
After the Crisis on Infinite Earths, DC Comics was stuck with trying to figure out how the Legion of Super-Heroes could exist with no Superboy, since he had been a intregral part of their origin, though he did not exist after the reboot. It was decided that Superboy was part of a reality created by the Legion villain the Time Trapper, one which he discarded once it was no longer of use to him. In this reality, no other heroes appeared other than the now deceased Superboy. When the Lex Luthor of that reality discovered a Phantom Zone projector in the wreckage of Superboy's home, he unwittingly released three Kryptonian villains General Zod, Quex-Ull and Faora, who then began to decimate this reality. With the help of Lex Luthor, our Superman was taken to that reality which was laid waste by these other Kryptonians. Superman captured and tried the villains. He found them guilty and using green kryptonite, executed them.
General Zod later reappeared on a Krypton that Superman and Lois Lane visited by traveling through the Phantom Zone. This Zod was still espousing Kryptonian purity and eventually had to be defeated through the combined efforts of Superman and Jor-El.
Later still, a figure rose to power in the eastern European nation of Pokolistan. Calling himself the General and dressed in a red suit of armor, the General stood toe to toe with Superman, even breaking the Man of Steel's jaw. It was later revealed that this General was in fact a Russian who had be exposed to Kryptonite radiation through his parents who were both cosmonauts. The effect on their son was that he terribly weak under a yellow sun but under a red sun, he possessed Kryptonian level powers. Contacted by the spirit of the Zod from the pocket universe, the General began to amass power, ultimately desiring to change Earth's sun from yellow to red and take Superman's place. He succeeded for a time, but with the help of Lex Luthor, Superman was able to defeat the General.
Zod gained great popularity when the character was portrayed in the first two Superman movies by Terence Stamp. Stamp's over-the-top acting style and scene chewing including the well known line "Kneel before Zod!" have made this purely secondary character in his original form, a well known character to the general public.