"Nyan Nyan" is a popular internet meme that features a cat, often depicted as a Nyan Cat, flying through space while leaving a trail of rainbows. The character is a pixelated cat with a Pop-Tart body, and it became famous for its catchy, repetitive song that includes the phrase "Nyan Nyan" in a high-pitched voice. The meme originated in 2011 and quickly gained popularity on platforms like YouTube and Twitter. It has inspired various remixes, merchandise, and even video games, making it a significant part of internet culture. The combination of cute visuals and catchy music contributed to its widespread appeal.