Injury Number 1

I did well, getting to day 4 of 2018 with no injuries of note. Today, however, I managed to give myself a nasty slice (its still throbbing, 10hours later) while building my new toy.
It's not even something one would usually associate with injury... Unless you're a certain sleepy princess, of course. Have you guessed what was in the box yet?

P.S. This was plaster number 7 or so. I saved you from the gore shot. You're welcome.