Windows 8: terrible cursor appears seemingly at random

Sounds like a graphics driver crashing based on the black screen and full redraw - look for a pop-up in the notification area next time it happens. In the meantime, check for updated graphics drivers for your graphics card.

I just had this issue and I was able to fix it by quickly shaking the mouse back and forth on the screen that was having the issue. Based on my symptoms and this forum link, I would say it has something to do with the graphics card/driver. I didn't update my drivers, though, and I have not had the issue again.

I have a three monitor setup and the cursor was only messed up on one of them - as I would move the cursor between the different monitors, it would go back to normal on two of the screens, and appear as the glitch on the one. I'm not sure if it was necessary that I shake it on the screen having the issue, but that's where I tried it and it went away.

It's a bug in the AMD/ATI software and it's been there for some time.

If you need a quick fix and restarting isn't an option, go to Control Panel > Mouse > Pointer Options > enable Display Trails. Then disable after restart to maintain your sanity.