Transmutation of the limbs

With the mastery of animal instincts, you get proficiency in survival. You can change your limbs into an animal form. This can give you extra speed, give you extra damage, give you extra AC or give you extra health. The extra speed can be calculated by your normal speed minus double your level. The extra damage is calculated by 2 times your biggest modifier in d4s.  The extra AC is the constitution modifier plus your level. The extra health is your health minus triple your level. The body parts in question can only be changed 5 times a day or you shall become that animal permanently.