Brun is main antagonist of the Buzz Lightyear of Star Command episode "42".
Brun is the leader of a group of space pirates known as the Valkyran Raiders, known for her strong belief of the Valkyran ways as she loathes Star Command and the Galactic Alliance. She believes that they moved in on Valkyran territory and has made it her purpose to fight against them by crossing into the Alliance's borders and attacking cargo ships. She is aided by her second-in-commands Hilda and Sig.
Despite appreciating a good battle, she knows when her forces are outnumbered and a retreat is in order. Through this, and through entering battle personally, she shows that she does not consider herself above her fellow Valkyrans and is not willing to pointlessly throw lives away. It also shows that she is neither afraid of getting her hands dirty nor afraid of defeat. However, her speeches and open derisiveness of "civilized" products such as Jo-Adian processed cheese spread, which she called "noxious swill", also indicate how she is set in her ways and not very receptive to change and new ideas.
She first appears when she and the Valkyran Raiders tried to raid a cargo ship, only for Team Lightyear to arrive to the scene. Vowing revenge on Team Lightyear, Brun orders her posse to retreat as their ship disappears into the unknown.
As Team Lightyear uses a new sensor to detect invisible ships, Bruns orders her ship to fire at their ship. However, the sensor created a new personality known as "42", which allows her to take control of the ship to avoid fire, much to the team's surprise. 42 then takes out the Valkyran ship's tailgate, forcing them to retreat once again.
As XR finally learns about 42's presence, he attempts to tell the rest of the team, but they don't believe him and 42 refuses to speak out to them due to her feelings being hurt by the team. At Star Command, XR and Buzz had a fallout, leaving XR to leave with 42 in the ship. However, the Valkyrans caught wind of their location and use a tractor beam to pull the ship in, taking XR as prisoner. Buzz, Mira and Booster then head to the rescue by using a spare but worn-out ship to get themselves pulled into Brun's ship, as Brun plans to dismantle both of Team Lightyear's ships for a price.
As Team Lightyear manages to rescue XR and escape in their ship, Brun caught wind of their escape and orders her posse to catch them. However, 42 reveals herself to the team and navigates their ship to avoid fire again, this time, blasting Brun's pod to spiral around. Realizing now that she has lost, Brun and his posse are forced to retreat away for good.