Dexter's Laboratory S03 E07 Copping an Attitude

"He skips grades. She just skips"

Because of his exceptional grades Dexter's school and parents have decided that he can go to college. At first Dexter is happy to be there so he can fill his mind with college knowledge, but in the end the students influence on Dexter allows him to do college pranks sending him a one way ticket back to Huber Elementary School.