The Reflex Hatchet is a human designated name for a Na'vi weapon which bares some sembelance to the North American tomahawk except for two things; the blade is curved in such a way that the bottom tip can be used to dig into skin and possibly break either tissue or bone. The other part is the handle, which is slightly curved forward with the blade while the lower portion of the handle is curved back, allowing an expert user to swiftly twirl it in an event to protect one's self from an attack upon the wrist.
The hatchet itself is made from Banshee bones while the blade was created from a banshee talon. The Tipani are known to melt Unobtanium in a way that allows an expert craftsmen to dip the edge of the blade with the mineral, creating a metallic edge that gives the hatchet a better chance of cleanly cutting off a limb if possible.
Most notorious use for this hatchet was during the Battle of Pandora when a warrior of the Omaticaya named Ta'zi utilized it in sticking the bottom portion of the blade into the human's face with the mask still applied and when he pulled the blade in the opposite direction with extreme force, not only did his mask came clean off but so did his lower jaw.