Homo sapien has evolved to the point where they have no natural weapons per se, but have may use their body as weapons outside the norm of daily existence.
A cats claws, as an example ARE natural weapons, as a dogs teeth, a snakes fangs, and a birds beak, etc. All there and in the evolutionary process designed to be used on a daily basis as a NATURAL weapon to allow the species to survive. Man does not possess the NATURAL strength, agility, or natural weapons of its nearest genetic equivallent. However that does not preclude man from DEVELOPING natural weapons. The difference is animals that possess them, have them naturally and no developement is necessary. Animals fight effectively instinctively, no training necessary. A man's hands MAY punch but is not designed to, and without developemental skills will probably break if used as a weapon, etc.