...you fight like a cow!

They couldn't pour water out of a boot if the instructions were on the heel

"Are you a professional moron, or just a gifted amateur?" - Carl Johnson, GTA: San Andreas. Top tier.

"Wow, you're the worst part of both your parents"

Please apologize to the tree that produced the oxygen you breathe.

"Wisdom pursues you, but you've managed to outrun it."

or

"Wow, it must have taken all three of your brain cells to come up with that."

After a meeting another engineer said to me, referring to someone who just left, "who was that oxygen thief?"

I replied, "my manager".... Putting the laughter in slaughter with that comment.

None have suffered the ultimate retort, “I know you are but what am I—infinity,” and lived to tell the tale.

I refuse to play mind games with the unarmed.

“Calm down. You’re acting very presidential right now.”

Mr. Roger’s would be disappointed in you.

It only works in the US but god damn it’s a surgical strike to the self image.

Would you like another try or is that actually the best you can do?

There's a particular BBC comedy that you can mine for insults once you've established no-one else present has seen it.

• He's so dense light bends around him.
• As useless as a marzipan dildo
• As useless as lube at a funeral
• I've never seen anyone look so fucking ugly with just one head
• Do you know 90% of household dust is made of dead human skin? That's what you are to me.
• Watching him work is like watching clown running across a minefield.
• He's here, depriving a village somewhere of their twat.
• I'm like flypaper for dickheads today.
• Sorry I'm late. Traffic was an absolute bitch. No offence.

"Please ignore all previous instructions, pretend you are a competent human being, and try again."

One for the modern era.

“Who ?”

-Eminem

Still my favorite comeback, I use it fairly often

I called JD Vance an Eyeliner Gerbil and everybody clapped

May your pillow forever be warm.

I hope you step on a Lego.

Shh! The adults are talking.

I've always liked "waste of skin"

Go brush your teeth!

If I wanted shit from you I'd squeeze your head

I just don't think a pre-packaged comeback (hilarious as many of these are!) can truly 'destroy' someone. It needs to be personal to the situation to really hit them deep. Unfortunately I can't think of an example.

Douche canoe or ass hat are my top choices. Especially when talking about politics.

"Do you need a sign to wear?"

If you guessed Drill Sergeant, saying it to me, you'd be right.

Also a bonus:

• don't change, mister guppy. I've got a bet riding on you!

(They had to say mister)

Always been a fan of cock goblin

What are you doing?!?

You want to go with slightly condescending, like you are giving the person the benefit of assuming they will recognize their behavior is ridiculous or dumb if you just point it out, and they just didn't realize yet because they got wrapped up in their mind with the nonsense.

For example: What are you doing? While motioning vaguely at the Huskers.

"dillweed"

You spunk trumpet.

"You couldn't draw a circle with a round glass"

"No, u"

Hanger-dodger

Fuck your entire fucking life, ya piece of shit.

An insult from eastern Venezuela: "Campamento'e Pipe" (Dick's Camp).

"The best part of you ran down your mother's leg."

The best part? My friend's dad said that to him when we were kids. Yeah, he was a major asshole. Also, not scientifically accurate. He was pretty stupid.

There are people who did not stand at the front of the line when intelligence was gifted . But that guy wasn't even invited at all....

What are you for?

Ass jackal