I remember this from the era when building websites with FrontPage and DreamWeaver was still a thing. There were sites with catalogs of those "apply cool effects to your website by copy-paste this snippet to your HTML source file", and a clock following the mouse cursor is definitely one of them! Fun times.
I had a GeoCities page and really wanted to try the cursor effects/followers, but they never seemed to work. I kept trying to add them and never saw anything... until I looked at the site on a friend's computer in IE and the screen just exploded with cursor followers. I was primarily a Netscape/Firefox user and didn't consider that my browser might not support the effects!
My fan site for the TI-86 graphing calculator (first draft done as part of 5th grade Computer Class, revised to get extra credit in my algebra class a few years later) used it! I had no idea what Javascript even was, but I knew how to view source and knew that if I pasted in all the magic between <script> tags from my computer teacher's website I'd get the cursor effect. He (or the original dev…) had very well-annotated code that included a bunch of variables you could customize.
I don't recall ever seeing it in the wild, but I remember it as a JS script you could add to your site from a page that I think was http://www.dynamicdrive.com/
I may have played around with it on a couple of HTML pages written in Notepad way back.
