I know a guy at my high school he is a big guy and a 6th grade idiot called him "a fucking fatass" but that is not the insult he actually turned around with an evil look in his eye and with voice that resembled a growling Rotweiler said to the 6th grader
"Well satan rapes your mother at night."
Another good one is when your in a back and forth with some you hate and they ask you "What do you want me to do?" you respond with "I want you to get cancer."
"Well satan rapes your mother at night."
Another good one is when your in a back and forth with some you hate and they ask you "What do you want me to do?" you respond with "I want you to get cancer."