Weapons that don't exist but should...

The Squirrel Exploder would come in handy for just such an occasion as this... and according to the Uncyclopedia, this weapon:

...sends out a powerful sonic pulse that disrupts squirrels' molecular structure, turning them into fiery furballs of flaming death. Unless you're really annoyed with squirrels, however, this weapon is of little use. That is, of course, unless it is combined with the patented EoH Cannon, EoH standing for 'Essence of Hazelnut'. This will coat a victim from head to toe with a sticky substance that exudes a powerful smell of these nuts over a wide area, attracting all sorts of undue attention from squirrels. The Squirrel Exploder can then be used to explode these rodents and cause grievous bodily harm to the hapless victim. Nothing hurts like having red hot squirrel guts embedded in your skull.

For maximum efficiency, the squirrels can later be reassembled with the Squirrel Desploder. Waste not, want not and all that.

You can go check out some of the other ideas for weapons that don't exist right now but ought to. Yes, I realize that this "weapon" is actually meant for the person covered in Essence of Hazelnut, but I'd use it just for the sheer joy of offing skwerls.