When Lois Lane went to a charity show, she watched as a slapstick comic hit Toto the chimp in the face with a pie. Wiping his face clean, Lois won the chimp's instant friendship. Later, Lois discovered that Toto was to be sent into space via a rocket that very week, and she covered the story for a TV network. While in his space satellite, Toto was bombarded with radiation after a collision between two meteors - one made of uranium, and the other containing kryptonite.
Upon his return to Earth, Toto appeared unaffected by his experience, but moments after he left his capsule, he began to grow to a tremendous size. Recognizing a friendly face in Lois, he picked her up. Thinking Lois was in danger, Superman flew to the rescue, only to be floored by Toto's new power - kryptonite vision.
Though not malicious, Titano - as Lois renamed him - was strong and clumsy enough to cause a great deal of damage and to potentially cause much harm. Lois finally managed to use the ape's tendency to mimic others to get him to wear a pair of lead spectacles, which protected Superman from his kryptonite vision. The Man of Steel hurled Titano into the prehistoric past where he would be among other giant creatures.
Superman encountered Titano again when a machine from an alien world transported him back to the present. Jimmy Olsen (as Elastic Lad) used a serum given to him by the Legion of Super-Heroes to duplicate the powers of Colossal Boy and, as a giant, he overcame Titano. Allura of the Ashtar system then took Titano to her own world of giants, where the huge ape found a mate.
Later still, the Atomic Skull transported Titano back to Earth and placed an implant in his brain that allowed the Atomic Skull to control the ape telepathically. Superman knocked the Skull unconscious and returned the docile Titano to his world of giant creatures.
In the new 52, we see Titano in a laboratory where scientists are studying him as well as other giant monsters that the Man of Steel has fought over the years. It is later implied that the replica of Superman who appears in Superman #5 killed Titano along with these other beasts.
Adventure Comics #295 features Bizarro-Titano, with Blue Kryptonite vision.