Lorca's menagerie was a room aboard the Federation starship USS Discovery in 2256 that was used primarily by Captain Lorca. This room had a collection of items, most of which were weapons, in addition to a collection of biological specimens. (DIS: "Context Is for Kings") Lorca called it his own “private research area", though the official name was his "menagerie." (DIS: "Magic to Make the Sanest Man Go Mad")
It was a zoo of weapons and animals. There were phasers, disruptors, daggers, and swords from a variety of cultures, and a Tardigrade, kept as a science experiment inside a containment pen. Other biological specimens included were a dissected Tribble, several Cardassian voles, and the skeleton of a Gorn.
Background information
In an interview in AT: "Context Is for Kings", the second episode of After Trek, host Matt Mira interviewed Executive Producer of Discovery, Aaron Harberts, who gave the name for this room.
During the interview, Harberts revealed that the Gorn skeleton was a deliberate hint at Lorca's eventual character arc. Since the United Federation of Planets (as of the time of filming) weren't supposed to have made contact with the Gorn until 2267 in the Star Trek: The Original Series episode "Arena", Lorca having a Gorn skeleton was supposed to hint at the fact that he wasn't from the Federation, nor from this universe at all. Harberts also explained that because Lorca was mysterious and had a lot of secrets, they wanted a set different from the ready room, which he could prowl around in; a set that added to the mystery and animal-like nature of his character.
Later in that same After Trek episode, a behind-the-scenes clip was shown about the props made for the room. Most of the props were made from silicone and polyurethane resin. The Gorn skeleton was a heavily modified Human skeleton. The skull of the Gorn was custom sculpted and reproduced in translucent resin.