Lycanthropy can be an interesting option.
Aspect of the Beast
Whether by magic or a curse of your blood, some part of you is more beast than man.
Prerequisite: wild shape class feature, see Special.
Benefit: Your bestial nature manifests itself in one of the following ways. You choose the manifestation when you choose the feat, and then you cannot change it.
Night Senses (Ex): If your base race has normal vision, you gain low-light vision. If your base race has low-light vision, you gain darkvision out to a range of 30 feet. If your base race has darkvision, the range of your darkvision increases by 30 feet.
Claws of the Beast (Ex): You grow a pair of claws. These claws are primary attacks that deal 1d4 points of damage (1d3 if you are Small).
Predator's Leap (Ex): You can make a running jump without needing to run 10 feet before you jump.
Wild Instinct (Ex): You gain a +2 bonus on initiative checks and a +2 bonus on Survival skill checks.
Special: A character that has contracted lycanthropy can take this feat without having to meet the prerequisites. A ranger who selects the natural weapon combat style can take this feat without having to meet the prerequisites (even if he does not select Aspect of the Beast as a bonus feat).