The Beluvian Demon Box was a special mystic containment device created years ago by Spindly Tam Kanushu to imprison the Sharbenian Demon. It was first shown in the episode Mad Maximus, where Spindly Tam asked for it to be moved from his temple, Betty and her crew were sent to retrieve it, but were followed by Maximus I.Q., Dr. Cerebral, and Pontifidora, who eventually, it seemed, released the demon, only for Spindly Tam to reveal to Betty that the box they had was a fake, containing a hologram demon, used as a decoy to distract the villains while the real box was transported.
Later, in the season two finale Takes One to Know One, Pandora snuck into Spindly Tam's temple to retrieve the box, which had been returned there, and succeeded in using it, along with the key and Paloma to release her father. However, Paloma harnessed her father's good powers and reawakened, teaming with Betty, her crew, Spindly Tam, and Admiral DeGill, together, they imprisoned the demon back in the box, along with Pandora. Spindly Tam then took the box back, promising to keep it in a secure area.