The poisonous Bibi Bugs (ビービ虫,Bībi Mushi), created by Buredoran of the Comet, are living products from the dark aspects of previous alien races Warstar conquered. When a monster would be defeated, Buredoran would send 6 Bibi Bugs down. They would then land on the monster, each generating Brajira's symbol, with the symbol of the monster's faction appearing in the center between them. After that, the monster would be revived as a giant. When Warstar fell, Brajira kept the Bibi Bugs' hive to utilize them for the Yuumajuu before Kinggon takes it. In his final battle, Kinggon used it to summon Bibi Bugs to enlarge himself, discarding the hive afterwards. Following Kinggon's death, the Bibi Bug Hive somehow ends up falling into the ocean, where it sinks and comes into Metal Alice's possession, modifying them to convert Bibi Bugs into Bibi Nails to enlarge Matroids by burrowing into them. After Matrintis's downfall, Brajira reclaims the Bibi Bugs for himself and puts them to use in his Earth Salvation Plan.
Eventually the Bibi Bugs are destroyed after Brajira's death. However, one Bibi Bug survives and evolves into a humanoid form called King Bibi (キングビービ,Kingu Bībi) who enters the body of Yumeko Hoshino in order to execute a master plan that would destroy the Goseigers and everything they stood for in order to avenge his kind while feeding on the darkness in human hearts. However, King Bibi's plan fails and he is destroyed soon after by Ground Gosei Great.
The Bibi Bugs are a reference to B-movies, in keeping with Goseiger's theme of its monsters being named for various Hollywood films.
The circle that appears in front of a defeated monster about to be turned giant is similar to the circle that appears when Kamen Rider Rey and Kamen Rider Arc transform.