Ratthew is a recurring black rat patient in the Roblox anomaly-hunting horror game Animal Hospital who serves as a critical, fan-favorite lore character because he is one of the only individuals in the building who actively acknowledges that the facility is a highly dangerous environment. He appears sequentially across work shifts 2 through 6, having spent a long period living a homeless lifestyle hiding inside the hospital's ventilation systems to escape the mysterious "Animal Corporation" that hunts him like an anomaly. Over the course of five distinct interactions, he slowly opens up to the player after realizing they treat him with genuine kindness, admitting that his small size allows him to sneak around, hear classified conversations, and see the dark secrets others completely miss. Before his fifth and final departure—fleeing because the Corporation is closing in on his position—he sits on the reception desk, tells the player his final story, and leaves behind a special desk key stolen from the doctor. Taking this key to Room 5 and tearing down a wall poster reveals a hidden vault containing a photograph of his missing twin sister, Rattina, (his sister) revealing a dark experiment: Rattina was successfully mutated by the facility into a horrifying creature known as "The Stalker." This makes Ratthew a deeply paranoid, distrustful, and secretive character who relies on a cynical, sneaky exterior to mask his profound gratitude and protective bond toward the player. He acts as a sinister but helpful oracle, spouting ominous warnings and cryptic remarks to tell the player directly not to trust the doctors or anyone else in the building. He is a fiercely anti-corporate rebel who successfully snuck into the accounting offices to chew through and destroy classified government experiment reports to stall their progress. Ultimately, his entire motivation for risking his life inside the dangerous hospital is an unwavering, tragic devotion to finding out what happened
