The controversial gag occurs in “Promortyus,” the seventh episode of Season 4, which aired Sunday, and depicts the titular characters battling alien adversaries. Upon approaching two enemy buildings that resemble New York City’s Twin Towers, Rick and Morty fly around the towers and attack a harbor instead.

“Honestly, I’m proud of us for not …” Rick says.

“Totally, would have been cheap,” Morty retorts, to which Rick adds, “Low hanging fruit. We’re better than that.”

While flying above the harbor, though, the duo decide to re-create the Pearl Harbor bombings and joke about it later at the dinner table.

“We almost did a 9/11, we went with the Pearl Harbor. We’re pretty classy,” Morty says.

Not all “Rick and Morty” fans found the joke classy, taking to Twitter to express disbelief.

“Is Rick and Morty still doing 9/11 jokes?” wonders one social-media critic. “Because wow, that’s so funny in 2020.”

Another disillusioned fan comments, “no they didnt … omg 9/11.”

“Not Rick and Morty with the 9/11 jokes,” laments another.

“This season sucks and on top of it your making 9/11 jokes?” fumes one hater of the darkly satirical series.  “How about instead of making two shows that suck make one good one?”

However, for others, the gag hit the mark.

“They skipped 9/11 and went for Pearl Harbor I love this show,” exclaims one “Rick and Morty” die-hard. 

“Loved the 9/11 bit,” says another.