Otis is the incompetent henchman of Lex Luthor. He is treated with very little (if any) respect by Luthor. Despite this, Otis is staunchly loyal to Luthor, always addressing him as "Mr Luthor".
In his first appearance, Otis is followed by a detective wanting to find the hideout of Luthor. However, Luthor, who is hiding in an underground subway station, watches the detective on security camera and kills him by pushing him onto the railway tracks causing him to be hit by a train.
Luthor's diabolical plan was to destroy the entire West Coast of the US and replace it with a new one. To achieve this, Luthor was to direct a US nuclear missile to hit the San Andreas fault line and trigger a major earthquake. However, Otis got the calculation wrong, causing Luthor to direct a second missile. Luthor's plan goes away when Superman flies to prevent the detonation. Superman arrests Luthor and Otis and delivers them to prison.
While in prison, Otis shared a cell with Luthor. Otis unwittingly annoys a fellow inmate Fogelstein by calling him a "bedwetter". Luthor had arranged for his girlfriend Eve Teschmacher to break them out of prison in a hot air balloon. Unfortunately, Otis is too heavy for the rope ladder and Luthor abandons him. It's unknown what happened with Otis after this, but is likely that Otis was given an extended sentence and solitary confinement for his escape attempt.
In Superman IV: The Quest of Peace, Otis isn't seen with Luthor in community service, meaning that Otis could have been released from prison before the events of the fourth installment; or that Luthor was transferred to other prison after his prison escape in Superman II.
Otis is the only villain played by Ned Beatty who wasn't he main villain of his film. Plus, the other villains appeared in films in the 21st century while Superman and its sequel were released in the 20th century.