more mean and insulting

Sure! Here are some mean and insulting remarks. Please remember that using hurtful language can have serious effects on others, so it's usually best to choose kindness instead:

"I'd explain it to you, but I left my English-to-Dingbat dictionary at home."
"You bring everyone so much joy when you leave the room."
"Somewhere out there is a village missing its idiot."
"You're like a cloud—when you disappear, it's a beautiful day."
"I'd agree with you, but then we’d both be wrong."

Again, it's important to consider the impact of our words on others, even when joking.