Now this is cold.

Wendy’s has always crowned itself the burger king for using fresh beef in every burger, unlike most of its fast food competition. So when McDonald’s announced on Tuesday – National Frozen Food Day, coincidentally – that it will stop using frozen meat for Quarter Pounders and Signature Crafted Recipe sandwiches in a quarter of its stores, the Wendy’s Twitter account trolled the Golden Arches. Hard.

“Hey @McDonalds, heard the news. Happy #NationalFrozenFoodDay to you for all the frozen beef that’s sticking around in your cheeseburgers,” Wendy’s tweeted, kicking off several posts showing photos of alleged classic McDonald’s burgers that still use frozen meat. And each snap looked sadder and more squashed and overly processed than the next.

Wendy’s then wrapped it up with, “Some people are going to use fresh beef in SOME cheeseburgers, SOME of the time. We believe in using fresh, never frozen beef in every cheeseburger everyday.” Now that’s Frosty.

“We wanted to make sure that people aren’t confused about what is communicated and what is reality,” Kurt Kane, Wendy’s chief concept and marketing officer, told Business Insider.

They’re not the only ones trolling their competitors for laughs on Twitter. Delta swiped at United last spring with a pro-leggings post after the competing airline was slammed for banning two girls wearing stretch pants from a flight.

“Flying Delta means comfort. (That means you can wear your leggings.)” said the burn from Delta’s official Twitter account – complete with a winking face emoji.

Customers ate it up. It’s been retweeted 31,000 times, and scored 117,000 likes and counting.

These are just the latest brands building buzz by tweeting not-so-subtle digs at rivals.

It’s even been dished back at Wendy’s. When Wendy’s tweeted a snap of a tray loaded with chicken nuggets, a burger, fries and a soda captioned as “The 4 for $4 meal,” Burger King shot back with pic of a five-piece meal and the dig, “5 for $4, because 5 is better than 4.”

And Merriam-Webster nailed it with this tweet against rival Dictionary.com. The latter posted a pic of a woman holding a cup of black coffee with the “Pemberly by the Sea” quote, “I like my coffee with cream and my literature with optimism.”

Without missing a beat, Merriam-Webster tweeted back “There’s no cream in that coffee.”

Merriam-Webster has also gleefully called out President Trump’s colorful language, tweeting that the world “bigly” exists, but “deproximately” and “braggadocious” do not.

Or how about this 2012 gem, when Old Spice teased Taco’ Bell’s “fire sauce” for not containing any real fire. The taco chain tweeted back, “Is your deodorant made with really old spices?”

These punchy posts don’t always work, though. Denny’s made customers feel a little queasy with a tweet about eating babies after Beyonce announced she was pregnant with twins.

“Wow, bey has TWO buns in the oven! that’s just an expression by the way. please don’t eat those buns. they are babies,” it posted.

#Fail

This article was originally published on March 31, 2017 and has been updated with the latest Wendy’s vs. McDonald’s tweets.