"くコ：彡" is a Japanese emoticon that resembles a squid or jellyfish. It is often referred to as the "Big Squid" emote and is used in online communication to express surprise, shock, or confusion. The characters "くコ" represent the shape of the head and body, while "：彡" represents the tentacles. The emote has gained popularity on social media platforms and is often used in memes and humorous content.