The McRib, an elusive fan favorite at McDonald's, turns 40 this year, and the worldwide chain is celebrating with a 2021 trend. For the first time in the U.S., McDonald\u2019s is creating a limited number of NFTs (non-fungible tokens) in celebration of the sandwich's anniversary. Ten Twitter followers who retweet the sweepstakes invitation between now and Nov. 7 will receive the McRib NFT, a unique piece of digital art. The McRib, which first debuted in Kansas City in 1981, features a boneless pork patty with barbecue sauce, pickles and slivered onions on a toasted homestyle bun. (It has 520 calories, according to McDonald\u2019s website.) The McRib has a cult following, in part because it only makes limited or regional appearances. As it makes its way back to menus, fans track its whereabouts on a site called the McRib Locator. Its most recent nationwide appearance was 11 months ago, in December.\u00a0 "The internet boom and emergence of social media solidified the McRib\u2019s icon status," McDonald's noted in a press release. "The love of the saucy sandwich connected fans online...the hype around its annual return even gave birth to the phrase 'McRib Season.'"