A mini-drone helicopter or fixed wing can also kill with kinetic force alone...if targeted at the right place. No onboard projectile or bomb needed! (see my tag line)
Horse droppings.
I've had a rather large RC helicopter crap itself to death at high RPM and launch a blade at me that hit me in the triangle. The repairs cost about $240 but the blade that hit me didn't even snag a thread on my field jacket. That's an 18" wooden blade at max speed. I was very close when that happened.
/johnny
There’s a guy who had flown his RC glider to 498mph clocked with a radar gun. Might have hit 550mph when it wasn’t being clocked. I certainly wouldn’t want to be hit with that!
Video at link of glider doing 468mph.