I've got a few:
Ha, ha, ha!
- The way you so cross-eyed, you aim at the ground and miss!
- You're so stupid you run away from HIV on a bicycle
- You're so stupid when you fail a blood test, you ask for corrections!
- You're so fat when god said let there be light, he said "Move your fat bum out the way!"
- You're so old when god said let there be light, you flipped the switch.
- You're so fat you fell off your family tree!
- You're so old you have to put your penis into a refrigerator for it to get hard on!
- You're so gay when I called you a f***t, you chased me out me house with your purple purse!
- If someone is making fun of you, use this diss: Hey, brother, I think you better go home and save your mother because I think she just got f****d broken!
- You're so ugly you make a blind man see!
Ha, ha, ha!