Mordecai and Rigby in “Unfinished Business”

Mordecai

In closing, your theories had failed to prove that you're smarter – for your brain is no bigger than a WALNUT.

Rigby

Very funny Mordecai, but your paper is fundamentally flawed because your brain is made up of 99% CANINE BUTT CHEEKS.

Mordecai

There is still one irrefutable truth. You don't have a high school diploma! So I'm smarter than you! You IMBECILE!!