Bone Ballpoint Pens

Bone Ballpoint Pens
Fortunately these pens are not made of real human bones (or unfortunately depending on your point of view). Yet they are eerily real-looking plastic ones. Very fun and they write well - the problem is keeping them from being borrowed!
$1.84
Via amazon.com

Ninja Pen with Sound Effects

Ninja Pen with Sound Effects
It's the classic ninja pen: a knife that goes "SHHHING!" when the tip is clicked, and the ninja ballpoint extends, ready for you to write ever-so-deadly letters.
$4.99
Via vat19.com