Memesake
The origins or namesake of a meme. Namesake is generally what something is named after. Aka the origin of the name is the namesake. In the same way memesake is a craze, reference or meme based on a an image, video or event. This event would be the memesake or the origin of the meme.
That cat has enough character expressions to become a memesake.
The memesake for that is…
The memesake for that is…