[masklinn]

I was initially thinking Clocky, but Clocky was an alarm on wheels.

I don't think the propeller one had any name beyond "flying alarm clock" or somesuch, and the failure mode seems way worse: if the propeller shoots out an open window or wedges itself behind furniture you're hosed.

Plus finding a small propeller in the dark corners of your room while just woken up seems way too stressful a task, frankly.