Rawr's Talon is only obtainable after killing Rawr, a very powerful deathclaw inhabiting the Divide. This variant of a deathclaw hand is the only one of its kind. It is also the only one that can be made into a weapon, the Fist of Rawr.
Rawr is found in a dark cave across from the Boxwood Hotel roof, behind the overflowing pipe and irradiated pool.
Rawr's Talon is a quest item, and cannot be dropped from the player character's inventory.