- "I have spent time with many Jedi here, over the years, and I would like to believe I have absorbed some small piece of their wisdom."
- ―Arex, to Kirak Infil'a
Arex was a Jedi training droid who spent many years with Jedi on the River Moon of Al'doleem, a moon in the galaxy's Mid Rim. During the early stages of the Jedi Purge, Arex was present on the moon with Jedi Master Kirak Infil'a and was tasked by Infil'a with preparing the mountains defenses when something dark was approaching.
- Darth Vader: Dark Lord of the Sith 3: The Chosen One, Part III (First appearance)
- Darth Vader: Dark Lord of the Sith 4: The Chosen One, Part IV