The Onion just shed its sardonic skin.

More than 12 hours after an offensive tweet sent from its Twitter account attracted a barrage of criticism, the satirical news company posted a letter of apology on its Facebook page late Monday morning. In the tweet, which was sent during Sunday’s Oscars telecast, the organization used the "C-word" in reference to 9-year-old Quvenzhané Wallis, who was nominated for a Best Actress Oscar for her performance in “Beasts of the Southern Wild.” Wallis lost to “Silver Linings Playbook’s” Jennifer Lawrence.

The letter of apology, written by CEO Steve Hannah, was posted at around 11:30 a.m. EST and attracted almost 3,000 “likes” in less than 20 minutes.

“On behalf of The Onion, I offer my personal apology to Quvenzhané Wallis and the Academy of Motion Picture Arts and Sciences for the tweet that was circulated last night during the Oscars,” Hannah wrote. “It was crude and offensive -- not to mention inconsistent with The Onion’s commitment to parody and satire, however biting.”

Hannah added that “no person should be subjected to such a senseless, humorless comment masquerading as satire” and promised that the individuals responsible for the offending tweet would be disciplined, although he did not name specific staffers. He also said the organization has since instituted tighter Twitter procedures.

At around 8:40 p.m. on Sunday, the tweet in question was sent from the @TheOnion Twitter account, which has more than 4 million followers: “Everyone else seems afraid to say it, but that Quvenzhané Wallis is kind of a c--t, right?” the tweet said.

The post was promptly deleted, but several news organizations published screen shots of the offending tweet, provoking a slew of complaints and immediate calls for an apology.

“This was definitely the worst attempt at humor we’ve ever seen on behalf of 'The Onion.' And we have a feeling they’ll be issuing an official apology by the end of the day,” wrote Mediabistro’s Patrick Coffee on Monday morning.

Coffee was right on the money, as Hannah’s letter appeared on Facebook about 10 minutes later.

The public apology was a rare move for the 25-year-old Onion, which is well known for its wildly irreverent and imaginative headlines, and is typically immune to criticism. In 2008, the company apologized after running a photo of a real-life firefighter alongside a satirical story about a firefighter losing his “lifelong battle” with a fire. The firefighter’s elderly mother saw the story and failed to see the humor in it, according to a report by the Ottawa Citizen.

“We feel really crummy about it and we apologize to the firefighter in question,” an Onion spokesperson told the Ottawa Citizen at the time.