Volunteer Feline Detectives (Panthera leo) were a pack of detective lions that once lived in the caves of the Mortmain Mountains. The lions were once noble creatures trained by V.F.D. to detect smoke, and it is revealed in The Bad Beginning: Rare Edition that Beatrice and Bertrand Baudelaire once worked to train them. At some point, the fire-starting side of V.F.D. (including Count Olaf and his associates) took control of the felines.
The lions first appear in The Carnivorous Carnival. During their time at Caligari Carnival, the lions devour Olivia Caliban and The Bald Man with the Long Nose , but later perish when Count Olaf neglects to retrieve them from the lions' pit after setting fire to the Carnival.
The whereabouts of the remaining Volunteer Feline Detectives is currently unknown.
- In Lemony Snicket's A Series of Unfortunate Events we see a photograph of Aunt Josephine taming a lion. As she was a V.F.D. member it is quite possible that the lion was from this pack.
- In Lemony Snicket: The Unauthorized Autobiography, one of Gustav Sebald's films is called "Lions in the Cave."
- The Bad Beginning: Rare Edition (Mentioned only)
- The Carnivorous Carnival
- The Slippery Slope (Mentioned only)
- Lemony Snicket's A Series of Unfortunate Events (film) (Mentioned only)