General Zod is likely off the table because he died in "Man of Steel" and came back as Doomsday in "Batman v Superman: Dawn of Justice" -- only to die again. He'll probably stay dead this time. Here are five other options.
5. Parasite has the ability to temporarily absorb the energy, knowledge and super-powers of another being by touch, making him a tough adversary for the "Man of Steel." The most well-known comic book incarnation of the Parasite is Rudy Jones. In 2009, The Parasite was ranked as IGN's 61st Greatest Comic Book Villain of All Time.
4. Lobo is an alien born on earth -- in Mexico -- and works as an interstellar mercenary and bounty hunter. He was introduced -- although initially rarely used -- as a hardboiled villain in the 1980s, and remained in limbo until his revival as an anti-hero biker with his own comic in the early 1990s. In the comics, Lobo has already beaten Superman twice.
3. Metallo is a radioactive cyborg who depends on Kryptonite as his energy source, making him a very dangerous enemy of Superman. Kryptonite radiation can kill the man of steel through exposure alone, although Metallo's cybernetic enhancements make him very physically powerful. He is a former soldier who was used in experimentation by the United States Army.
2. Bizarro is the perfect imperfect duplicate of Superman, acting as his antagonist or ally depending on the situation. Originally created to be Superman's clone by Lex Luthor, his poorly constructed genetics caused him to become the opposite. For example, he has freeze vision instead of heat vision.
1. Brainiac is considered Superman's greatest foe after Luthor. The super-intelligent alien from the planet Colu has advanced mental abilities that allow him to work through robotic and even human proxies. It can be difficult to tell whether you're dealing with the original Brainiac, or one of his drones. His obsession with knowledge has led him to shrink down many cities to bottle size for transportation on his Skull Ship -- including Kandor on Krypton.