Their appearance is that of a giant squid monster that has skin and teeth similar to a Lucubra and four tentacles.
Vilgax first used them against young Ben at an unspecified point in time. He intended to feed Ben to them.
At some point after, Vilgax had several of them hidden under the sewers of Bellwood (the moist atmosphere being close to Vilgaxia's), where they laid in hibernation until the present, when the plumber Bill Gacks accidentally triggered a device that set their reawakening into motion.
Ben 10: Omniverse
- Bengeance Is Mine (first appearance)