Goa'uld-Ra

Ra is the villain in the original Stargate movie, and is established in the television show Stargate SG-1 as a Goa'uld. The character is based on the Ra of Egyptian mythology. He is played by Jaye Davidson in the film and Jay Williams in the series. In some scenes of the movie, the outline of Ra's original humanoid form can be seen. Stargate SG-1 contradicts this, retconning Ra as a canonical Goa'uld.

According to Stargate mythology, 10,000 years ago Ra voyaged across the galaxy searching for a new host that could sustain his dying form. He discovered Earth and found the native humans easy to repair using his advanced technology. He possessed the body of a young boy, and ruled over the planet as a god. During his reign, he seeded humans throughout the galaxy using the Stargate. Ra was the most powerful and cunning of the Goa'uld, holding the title of Supreme System Lord. His Queen was Hathor, his son was Heru-ur, and his brother (and enemy) was Apophis. Ra also defeated the Tok'ra Queen Egeria, and battled the Goa'uld Shaq'ran.

Five thousand years ago, the people of Earth rebelled against Ra and buried the planet's Stargate in Egypt. In order to avert another such uprising, Ra outlaws reading and writing on his other planets, including Abydos. In the Stargate film, an Earth team led by Colonel Jack O'Neil (his name was spelled O'Neil in the film and changed to O'Neill in the series) travels to Abydos after the Stargate is activated, to reconnoiter the area and if necessary close the way to Earth with a nuclear bomb. They are captured by Ra's forces upon his return to the planet. Ra plans to send the bomb back to Earth along with a quantity of naqahdah, which will amplify the explosion. O'Neil and his team escape and eventually incite a successful rebellion amongst the Abydonians. As Ra abandons the planet, O'Neil and Jackson teleport the active bomb to his ship by way of a ring transporter, destroying it and him. Ra's death draws the attention of the other Goa'uld to Earth, and creates a power vacuum amongst the System Lords that allows Apophis to become more powerful.

Ra has only appeared once on Stargate SG-1, in masked form, in the season 8 episode "Moebius". In that episode, SG-1 travels back in time to steal a ZPM from Ra, and inadvertently changes history into one where Ra took the Stargate with him after the rebellion on Earth. The original timeline is restored after a second version of SG-1 travels back and ensures that the Stargate is left behind. An unmasked Ra appears briefly in the alternate timeline of Stargate: Continuum as one of Ba'al's lieutenants.