Desktop Pets

Neko

(1988)

A cat that runs around on the screen, chasing the mouse cursor

Neko

https://www.yewknee.com/blog/neko-the-software-pet
https://eliotakira.com/neko/
https://ja.wikipedia.org/wiki/Neko_(%E3%82%BD%E3%83%95%E3%83%88%E3%82%A6%E3%82%A7%E3%82%A2)