"Teacher (Mighty Mountain)" is not an official name.
Teacher (Mighty Mountain)
April 9th 117
Gender Male
Animal Sheep (?)
Cow (?)
Hair color Dark brown
Complexion Tan
Job 3rd Grade Teacher
Cartoon debut "April 9th"
An unnamed 3rd grade teacher at Mighty Mountain Elementary School appears in "April 9th." He was about to start class, but the fire alarm went off and everyone had to leave the building. He was later walking in "The Wheel Deal" but he completely ignored Brain and Lydia.