Is Ratthew an Anomaly in Animal Hospital?

The short answer

The verdict is explicit: Ratthew is not an anomaly. What fools people is the camera staring. Several real anomalies give themselves away by watching the lens, and Ratthew sits in the office doing something that looks the same — so the first read is often "tase him." That read is wrong.

Why almost everyone suspects him

Named NPCs arrive at the same window as your patients, so the first job is telling them apart from the queue. Ratthew is the one that catches people out: he is a small black rat — white muzzle, buck teeth, curled pink tail — and he stares at the security cameras, which is a genuine anomaly tell, not a superstition.

One of the nineteen, Staring at Cameras, looks directly into the CCTV lens at all times, even while walking around, which a normal patient never does. A separate visual-channel anomaly, Staring, tracks you in person and on camera, with a head that can swivel further than a real neck should allow. Ratthew's habit sits right on top of that pattern. He is also small and odd-looking, which does not help the first impression.

He even admits it hurts that everyone treats him like an anomaly. That line only makes sense if the misread is constant — players are not inventing the suspicion; the stare is doing the work.

Tasing him because he looked at the camera is a known player mistake, and it is how people lose this questline. Tasing or shooting a normal animal costs −15 sanity, so you pay to remove a friendly visitor. The taser itself unlocks at the end of Shift 3, which is the same early window he first appears in (around Shifts 2–4).

How you can be sure he's safe

• He is not on the 19-anomaly roster. The game keeps a fixed list of 19 anomalies, split across three channels: look in person, take a polaroid, or check the CCTV. Eight of the nineteen are visible in person, three only on the printed photo, and eight more only on camera. Ratthew is not on that list. If he were an anomaly he would have a tell, a channel, and a page with the rest of them. He does not.
• He warns you in red text. While he is in the office, Ratthew flags you whenever an anomaly approaches check-in. Identification in this game is normally a job you do yourself, split across those three channels — and eight of the nineteen anomalies are invisible on anything but the cameras. A warning that fires at the window is a second opinion that does not care which channel the thing was hiding on. It does not tell you which anomaly, so it does not replace the check; you still have to look, photograph, or pull up the feed to know what you are refusing. What it replaces is the worst case: admitting one because it never occurred to you to check at all.
• His visits recur and nothing attacks you.He first appears around Shifts 2–4 and returns across roughly five visits. He checks in as an anonymous patient — "being small has its advantages" — then comes back. Anomalies are entities disguised as patients; letting one through the window usually triggers a Death Ritual, spawns a monster, or turns it into a Mimic that attacks patients and staff. Ratthew's visits play out as conversation, not an attack.

Put those together and the camera stare stops being evidence. It is a tell when the creature is one of the nineteen. When the visitor is missing from that roster, keeps coming back, and shouts in red the moment something hostile reaches the window, you are looking at an informant, not a disguise.

So what is Ratthew, actually?

A paranoid but friendly informant — and a patient. He introduces himself anonymously, later gives his name, and tells you to trust no one in this hospital. He chewed up classified documents in Ron's office and does not regret it. He uncovered a government secret and is being hunted for it. That is the paranoid half. The friendly half is the red-text warning, the fact that he keeps coming back, and what he leaves when he finally has to disappear.

Frequency is worth knowing because it changes how much patience he deserves. Barney gets up to three visits in a single shift across Shifts 2–7. Ratthew is far rarer — roughly five visits across an entire run, starting somewhere in Shifts 2–4 — and those visits overlap the same early block, so he is competing for your attention while Barney is running his own chain of requests. Let both of them talk. Tasing the rat because the camera feed looks wrong is how you pay −15 sanity to remove your own early-warning system.

On his final goodbye he hands you a key plus a note; the key opens the safe behind the cat poster in Room 5, at the far back-right of the hallway. Inside are a photo of his twin sister Rattina, a TOP SECRET briefcase, and a note that the experiment was a success — "Shadow can see everything now." That is the teaser, not the full file.

For the full Ratthew storyline and what's in the Room 5 safe, including the visit-by-visit dialogue and how the suitcase ties to other characters, go to his character page.