Mutant in Hospital Gown

The Mutant in Hospital Gown is a mutant Monster kept in the Facility. Since the Mutants are listed on the Whiteboard, this Monster may have been included with them due to it being a Mutant as well. It is later seen twice during the System Purge.

Physical Description and Attributes
While it resembles the Mutants in appearance, it is slightly different from them. This mutant's face is more grotesquely deformed than the other Mutants', and, unlike the other Mutants who are seen wearing orange and red jumpsuits and straight jackets, this one wears a hospital gown. Why or how this Mutant differs from others in its group is unknown.

In the Cellar, its unknown if this Mutant has its own summoning item, or if it can be summoned from the same gas mask kit as the other Mutants.

Appearances
The Mutant is released during the second or third wave of the Purge. It is first seen on one of many CCTV cameras, where it holds down a frightened Facility worker. Later, when Marty and Dana take the chance to escape the control room in the Elevator Lobby, the Mutant tries to ambush them. Luckily, Marty shoots it in the head and green blood oozes from its skull, killing it instantly.

Trivia

 * The Mutant in Hospital Gown is one of a small handful of Monsters we see get killed during the film. The others being Judah Buckner, Patience Buckner, and the Scarecrow Folk.

Inspiration
It maybe a reference to the mutant from Septic as it bears uncanny resemblance to him as they are both mutants in gowns originating from hospitals. It may be a reference to other horror films such as Mutants and The Hills Have Eyes, horror films about people who have been infected by horrible viruses or even real real life cases viruses and flesh eating bacteria.