One of my favorite toys in 2nd grade was a pencil sharpener.

It was a small old fashioned cannon with a pencil sharpener on the bottom. Picked it up during a school field trip at a colonial museum. Teacher and classmates thought nothing of it sitting on my desk because they recognized it from the field trip.

BUT!!!...there was actually a spring mechanism where you could load in broken off pieces of pencil lead and fire it out the cannon! Thing had a good 20 foot reach. Even better, the projectile was so small that it couldn't be seen. People would get hit by this invisible thing and not know what the heck it was.

Months of entertainment during class.