The Book of Monsters is a character in Nexo Knights.
The Book of Monsters is a book with a sinister face and sharp teeth. It has a red reptilian tongue poking out the right side of its mouth and gold corners. It can be hinged onto the back cover and has a card with a monster imprinted onto it.
Monstrox was an evil necromancer who was a big threat to all of Knighton. Merlok used all his magic for a spell that transformed Monstrox into the Book of Monsters. Monstrox's powers were split into eleven spellbooks:
- The Book of Evil
- The Book of Chaos
- The Book of Fear
- The Book of Anger
- The Book of Deception
- The Book of Destruction
- The Book of Revenge
- The Book of Greed
- The Book of Envy
- The Book of Cruelty
- The Book of Betrayal
The Book of Monsters was kept contained in Merlok's library.
Many years later, Jestro stumbled onto the Book of Monsters, who manipulated him into becoming evil. As a result, Jestro used the Book of Monsters' ability to summon the Lava Monster Army and begun a quest to reclaim the eleven spellbooks.
It turned out that the Book of Monsters had a secret plan that involved obtaining the right host in order to recreate his Monstrox body.
- In the TV series, Monstrox/Book of Monsters is voiced by Mark Oliver, who also voiced Garmadon in Ninjago: Masters of Spinjitzu.