Help identifying mystery clip

[chasc]

Just performed an oil change this weekend. When removing the engine cover I heard something metal hit the ground and found this black metal clip. I'm not sure if I knocked it off the cover or if it had been laying on the cover (dropped from above) and fell on the ground when I was moving it. Does anyone recognize where it would have come from? I searched around under the car for a while but couldn't find any more like it or clear spot that it had come off of.