Benson bought his products to keep Mordecai and Rigby from slacking off, but they manage to constantly evade him, causing Benson to accidentally summon him to the park to watch over everybody and as a result, he cannot leave until they die (due to the contract that Benson signed without even reading it). After spooking everyone with his gazes, Mordecai challenges him to a staring contest in which Peeps must leave if Mordecai wins but if Peeps wins, he will harvest their eyes.
Benson
Mordecai