Rotter

Mr. Rotter is an undead and presumably from Romania, who teaches Dead Languages at Monster High. He was introduced in the webisode "Idol Threat" and is voiced by Yuri Lowenthal.

Personality
Mr. Rotter believes in order and little patience for students try to cause chaos. He is, however, not a strict teacher and enjoys to spark enthusiasm for both his classes and others in the students. This means that sometimes Rotter fails to understand when students are not enthusiast about some of the classes. He is known for never given 'A's.

Classic Monster
Mr. Rotter is an unspecified type of undead, which coincides with his teaching of Dead Languages as he was alive when they were. He appears to be speaking in a Romanian accent, playing on the Bram Stoker-inspired idea of Romania as the nation where the night is ruled by the undead.

Volume 1
In "Idol Threat", Cleo de Nile had studied all night for a particular test and was offended when she didn't score higher than a 'B+', despite doing the work to perfection. In order to get her rightful 'A' from Mr. Rotter, she used an idol with persuading powers on him and got it.

Volume 2
"Fear the Book", "Desperate Hours"

Rotter tried to start his class in "Back-to-Ghoul", but got hit by a snowball thrown by Frankie Stein in a fight with Abbey Bominalbe. He sent them both to Headless Headmistress Bloodgood's office.

Fright On!
After Dead Languages, Frankie Stein and Draculaura talked about how all the languages Rotter taught sounded alike, followed by a mocking imitation oftheir teacher by Draculaura. Mr. Rotter noticed, but thought she was trying to follow his teachings and so gave her the advice to let her 'R's roll.

Volume 3
Rotter functioned as referee during the casketball game between Monster High and the West valley Mages in "Super Fan".