The Barbarian's Rage Power Lesser Beast Totem adds two claw attacks:
While raging, the barbarian gains two claw attacks. These attacks are considered primary attacks and are made at the barbarian’s full base attack bonus. The claws deal 1d6 points of slashing damage (1d4 if Small) plus the barbarian’s Strength modifier.
Note that these are gained only when the rage starts.
The Druid's Wild Shape gives you a few Natural Attacks as well:
Wild Shape: At 4th level, a druid gains the ability to turn herself into any small or Medium animal and back again once per day. Her options for new forms include all creatures with the animal type. This ability functions like the beast shape I spell, except as noted here. [...]
Beast Shape I is a polymorph spell, of which the Magic rules state:
In addition to these benefits, you gain any of the natural attacks of the base creature, including proficiency in those attacks. These attacks are based on your base attack bonus, modified by your Strength or Dexterity as appropriate, and use your Strength modifier for determining damage bonuses.
Get I add these claw attacks on my animal shape, if I Rage after entering Wild Shape?
Strongly related, if I'm a mounted Barbarian, sharing rage powers with my mount, would my horse get claw attacks in addition to its hoof attacks?
My brain wants to say that my horse doesn't have the limbs for those attacks, but I can't find any RAW saying anything on this topic.