The Reptile Room in Dr. Montgomery Montgomery's house was where Dr. Montgomery would collect his reptiles. It was also a library where a herpetologist could do their research. Known reptiles included:
- The Incredibly Deadly Viper
- The Mamba du mal
- The Virginian Wolfsnake
- The Alaskan Cow lizard
- The Dissonant Toad
- The Inky Newt
- The Irascible Python
- The Green Gimlet Toad
- The Androngynous Cobra
There are also some reptiles that are never given scientific names but are worth mentioning.
- A fat toad with wings coming out of its back
- Two-headed lizard with a yellow stripe on its belly
- A snake that had three mouths, one on top of the other
- Snake with seemingly no mouth at all.
- Lizard that looked like an owl with very wide eyes
- Toad that looked like a church with stain-glass eyes.
Most of the books are about snakes and lizards including volumes on An Introduction to Large Lizards and The Care and Feeding of the Androgynous Cobra. There are also appear to be books on geographic locations such as Peru and about creatures from various locations including The Big Peruvian Book of Small Peruvian Snakes, which Klaus reads for research in preparation for the expedition to Peru. However, some of the books in the library have secret chapter that are linked to VFD. This includes Remarkable Phenomena of the Mortmain Mountains, which Quigley Quagmire reads when he ended up at Dr. Montgomery's home after escaping the fire. There is a hidden chapter in the book that informs the reader about the Vertical Flame Diversion and the Vernacularly Fastened Door. Also, according to Jacques Snicket, there was an important file he had to find.