The spell I'm thinking of allows the caster to grow a tentacle, wing, or hoof, any of which can be used as a secondary natural attack. It takes the target 10 minutes of 'practicing' with the limb in order to get used of utlizing it. It lasts 1 hour per caster level. I *think* it's a lvl 3 spell.
If anyone has heard of this spell, can they tell me the name of it and what book it is found in? Thanks!