Prank Callers

S1, E9: After watching videos of the Master Prank Caller Mordecai and Rigby decide to make prank calls. They prank call Benson but he gets mad and tears the house phone off the wall. They use Pops' cell phones so they could prank the Master Prank Caller numerous times using various names although they fail to fool him. Eventually he calls Mordecai and Rigby and sends them to 1982. Mordecai and Rigby must then engage in a battle of prank calls against the Master Prank Caller to send them back to the present. After learning that the Master Prank Caller is a person Mordecai and Rigby take him to the present where they prank call Benson into having his chair sent to the 1970s.