Maths Teacher

The Maths Teacher was a minor character from Regular Show who appeared in "More Smarter"                         "If you can solve this one math problem, you will be leaving this class with a diploma" - Teacher

History
When Rigby went to school, he fell asleep in math class. In his dream, his Maths teacher made a math problem that could get you graduated very quickly, and Rigby easily solved the problem and was given his diploma, only to wake up to see the Math teacher shout at him with all the kids laughing at him and making a fool of him.

Trivia
Even though he was part of a dream he exists as well.