How many books are in the gregor series?

There are 12 books in the Gregor the Overlander series by Suzanne Collins.

Here they are in order:

1. Gregor the Overlander

2. Gregor and the Prophecy of Bane

3. Gregor and the Curse of the Warmbloods

4. Gregor and the Marks of Secret

5. Gregor and the Code of Claw

6. Gregor and the Monsters of the Deep

7. Gregor and the Labyrinth of Bones

8. Gregor and the Threat of the Warmbloods

9. Gregor and the Dragons of Eternity

10. Gregor and the White Dove

11. Gregor and the Last Guardian

12. Gregor and the Key to the Kingdom