It’s a fork bomb. It exponentially forks processes in the background in an attempt to consume all CPU cycles.

I had a similar problem with one of my displays going wibbly like that every time I rebooted during POST and system boot. Only going back to normal once X started.

When I checked my monitor’s display settings when it was wonky, I found that it had the refresh rate set to 14hz and really strange resolution. Turns out it was the display port cable. Replacing that fixed it right up.