Superman, Vol. 2 #5 (1987)

The Mummy Strikes
After a tantalizing dream involving Wonder Woman, Clark rushes down to the Daily Planet. There he learns, that Lois Lane has been covering an archaeological expedition in South America. But the Planet has lost contact with her, and Perry wants Clark to fly to South America to see what is going on. Clark flies there as Superman and quickly changes clothes. Uniting with Lois, they meet Dr. Estevez who has been unearthing an ancient pyramid. There is evidence of an advanced society dating back in excess of 100,000 years. Not only that, but and underground silo shows the ancient culture to have been more advanced than even modern society. Clark explores the inside of the pyramid until he comes upon a gigantic over-sized mummy. The mummy comes to life and begins attacking him causing a cave-in. Clark pushes Lois outside the debris field and begins fighting the mummy with his super powers. It is obvious that this not a regular mummy, but rather a large mechanical robot. Lois and Dr. Estevez manage to claw their way inside in the hopes of rescuing Clark. When they find him however, he is lying atop a pile of debris and appears to be dead.
Release Date: 1987