It’s a math teacher from fpe who likes Oreos

Miss Circle has very long spiky hair with black horns, one of which has two white lines on it, as does the bottom of her hair. She lacks a neck, like many of the other teachers and students. She dons a black button up shirt with a white collar and white pants rolled up to the knee.

She also sports tall black combat boots. Instead of a hand, she has a drawing giant compass extending from her left forearm. The point of the compass is retractable, and has been used against students who have failed her class. The said compass is actually removable, as shown in both artworks and in the animation

Miss Circle is shown to be very cruel and violent once you fail your class. She shows no mercy towards students that fail in her class, killing them. She is also is known to play favorites, such as Zip, Oliver and Edward.[4] However, she still makes sure they follow the rules, as she scolds Zip and Oliver for tricking Claire.

Despite this, Miss Circle is also seen to be goofy and playful at times, but this could possibly just be a mask to hide her more murderous tendencies

She likes Oreos btw