Repgillian is a giant monster.
In "Mega Borg Power," Repgillian was created from mixing toxic chemicals, Lester Fortunes' old drawings (consisting of Changeling, Fernzilla, Torch Mouth, Ultra Vulture and Triplesaurus Rex), and Nukus' powers. Repgillian was then unleashed where it attacked Charterville. This creature was more powerful than anything the Beetleborgs had ever faced, and even Roboborg had trouble when he fought her. In a last-ditch effort, Roland stole the Astral Ax from the Crustaceans and called on Boron, which subsequently caused Boron to switch sides and join the Beetleborgs' side. It took the combination of the Mega Spectra Beetleborgs, Roboborg, and Boron to finally destroy Repgillian.