A rock. Rocks come in many shapes and sizes and can often be found just laying there on the ground when you need one. You can throw one, pick one up and smash something with it, chip one into an arrowhead or spear point or knife, use one in a sling or catapult or even just roll a big one down a hill. Probably the first weapon or tool man ever used.

Secret ninja moves from the government.

Go for the nads

A Bad Arse Sling Shot w/ Ball Bearings for Ammo

A sharp stick dipped in dookie... Or maybe a hatchet...

It should be legal to carry a sword.

Like open carry swords?

public opinion or an ice pick

The ninji star!

A sling. It worked for David.

a rubber and and a paper clip can make a grown man cry...

I've been taught hornet/wasp killer is a good underrated weapon.

Nuclear bomb

Mt wife has a lactose intolerance. If she eats ice cream she can be called weaponized.

A meat stick