I learned about a frog today that breaks a bone in its toe and uses it as a claw. That got me thinking, such a zombie or other monster in a game that uses its bones extruding out the body as a weapon would be great in a horror game. The idea of a bone sticking out of the body makes me uneasy, and that is why I think it would be great in a horror game. Instead of having a zombie with a weapon, its hand is gone and has a sharpened forearm bone sticking out of his arm.

Any thoughts on the idea? Are there any examples of this already in a game?

Bones poking through skin or sticking out in any way always makes my skin crawl. I think it is a fantastic way to spice up a monster. The addition to a "stabbing" weapon built into the end of a creature's arm can make for interesting gameplay if you have different wound types.