Melmacians are fictional extraterrestrial beings from the television series ALF, which aired in the late 1980s. They are known for their green skin, large ears, and a love for eating cats. The most famous Melmacian is ALF, whose real name is Gordon Shumway. He crash-lands on Earth and lives with the Tanner family, leading to humorous situations. The culture of Melmacians is depicted as quirky and eccentric. They have unique customs, such as celebrating a holiday called Melmacian Thanksgiving, where they eat unusual foods. The show explores themes of family, friendship, and the challenges of being different.