Neko is the Japanese word for cat, and chan is an affectionate suffix often added to names or cute characters, which is why the phrase feels instantly familiar in anime and internet culture even without a single famous source clip. Short spoken phrases like this travel well online because they are easy to recognise, easy to drop into an edit and easy to understand from tone alone. It is now commonly used in fan edits, reaction videos and cat compilations, where a brief, sweet greeting can set the mood before the main joke or moment arrives.