Most information given about Hydrus comes from the radio Easter eggs found in The Room: Old Sins. Hydrus was preceded in his position by The Circle's most gifted collector, who betrayed the organization and fled with some of their Null samples. He is considered a "valuable acquisition", though the voice on the radio refers to his methods as "vulgar". One radio message concludes by stating that despite his value, Hydrus will be kept under close watch to ensure history does not repeat itself.
Collector Hydrus considers stealing the sample from Waldegrave Manor, but decides against it, as indicated in the hint Easter egg at the end of The Room: Old Sins. However, The Circle seems to know about his wavering loyalty, as indicated in the radio Easter egg, and intend to terminate his employment.
Judging by the tone of his writings and hint messages, Hydrus is straightforward and focused in his work. He takes pride in his knowledge of the Null, and looks down on the police who are unable to comprehend the disappearances of Edward and Abigail Lockwood. He also seems to have ambitions and machinations beyond The Circle, and holds no particular reverence for his superiors that would prevent him from betraying them. He is cautious, biding his time for some unknown purpose.
- The character of Collector Hydrus is modeled after Jeremy Linares, a designer from Fireproof Games, who plays him in full-motion video for some cutscenes.