Mach is an NPC that can be found in-game, but will not enter the elevator. Mach is a blocky, light-skinned humanoid with dark brown hair tied in a low ponytail. She wears a curved purple top hat with a white ring, along with an open suit of the same purple color and a purple shirt. She also wears lighter purple pants and black shoes. Mach has a neutral facial expression along with red glowing pupils and always seems to have her hammer with her, which has a long brown handle, black grip, and bright red head. Mach also has the girl torso.

Mach appears in four floors: WHEEL OF, WALL OF, HALL OF, and OFFICE OF.

In WALL OF and HALL OF, she can be seen watching the players in various positions (on the side of the course) as they complete her incinerator challenge.

In WHEEL OF, she sits on a crate next to the wheel and makes comments depending on what the wheel lands on. If it lands on FUN, Mach will blow a whistle, signifying that Pilby will be coming to the elevator, and makes a comment about them.

In OFFICE OF, she sits on her desk, up in an inaccessible window talking on a phone, or on three crates stacked behind the desk, and she can be interacted with. When done so, she will tell you bits of things about herself, as well as Pilby. Players can also try to steal her Banhammer, in which she will fling the player away from the hammer and damage them.

In both WHEEL OF and OFFICE OF, hitting Mach with a Snowball, Tomato, C4, Tiny Foamer, Spray Bottle, Bowling Ball or Anti Voomba Mechanism will cause her to shoot a particle at the offending player, instantly killing them.

If MR, or Banrey, from the 2024 April Ghouls' Update, is in the elevator when the OFFICE OF floor starts, instead of being on her desk, she will be in front of the elevator doors as she swings her hammer at it, killing MR (or Banrey) before teleporting back to her desk.

In her 2024 April Ghouls' Update appearance, only the colors of her outfit, eyes, and hammer are changed. Her suit is now a dark orange, her eyes are teal, and the hammer is turned dark blue. 

I see her more of like a chill, calm female sounding person, sort of like folly but without the evilness, nothing to crazy but nothing to uncrazy, sort of just a neutral sounding person.