xeyes can be Actually Useful; two eyes always looking at the cursor...

your animal brain hardwired to discern the direction of gaze of the eyes facing you (citations appreciated)...

Helps me find the mouse cursor on a big screen if I lose track, even with small parallax angle.

On macOS, I just wiggle the mouse back and forth, and the cursor gets really big, it pops out at you.

I generally don't keep `xeyes` running. But it's a righteous, venerable hack.