The Overseer was the name given to a Rakatan guardian droid created during the height of the Infinite Empire around 30,000 BBY.
The droid supervised the construction of a temple on the planet Dantooine, ensuring its completion according to specifications and enforcing discipline among the slaves assigned to the project. As such, it was programmed to communicate in the ancient Rakata, as well as the languages of the Infinite Empire's slave species, including ancient Selkath and Tusken.
At the conclusion of the project and the execution of all slaves involved, the Overseer was reprogrammed by the Rakata, remaining at the site to provide information about the Star Forge to any of their species who sought it. This function would go unused, as no Rakata ever returned to the temple to access the Star Map within.
Millennia later, the two Jedi Revan and Malak would encounter the Overseer in the time of the Mandalorian Wars when they entered the temple, now reduced to ruins, seeking knowledge of the Star Forge to fuel their desire for conquest. The droid informed them that to enter the temple's penetralia, they would have to prove themselves "worthy" by showing their understanding of the reasoning of the ancient Rakata. The pair succeeded in this trial, beginning their journey across the galaxy to other Star Maps and initiating their transformation into Darth Revan and Darth Malak.
In 3956 BBY, the amnesiac Revan returned to the Rakatan ruins with Bastila Shan and encountered the Overseer once more. The droid, which gave no indication that it recognized the former Sith Lord, again informed the temple's visitors of the objective to which they were assigned. They also completed the task successfully, discovering the means by which Revan and Malak had learned of the Star Forge's location.