Monsters are powerful warriors that wield the mystical power of Kairu in the television series, Redakai: Conquer the Kairu. They come in all shapes and sizes. Warriors can transform into Monsters through Kairu. The most powerful Kairu warriors join the ranks of the Redakai, a force dedicated to protecting the galaxy from those who would abuse the power of Kairu.
- Some Monsters resemble Mechtogan from the anime series, Bakugan: Mechtanium Surge, such as Metanoid and Drudger.