Vermin Shape II

Transmutation (Polymorph)
Level: Alchemist* 5, Druid * 4, Hunter * 4, Magus * 5, Sorcerer */Wizard * 5, Warlock * 4
Components: V, S, M (a piece of the creature whose form you plan to assume)
Casting Time: 1 Standard Action
Range: personal
Target: you
Duration: 1 minute/level
Saving Throw: -
Spell Resistance: -
  This spell functions as vermin shape I, except it also allows you to assume the form of a Tiny or Large creature of the vermintype. If the form you assume has any of the following abilities, you gain the listed ability: Burrow 30 feet, climb 60 feet, fly 60 feet (good maneuverability), swim 60 feet, Darkvision 60 feet, Low-Light Vision, Tremorsense 30 feet, Scent, blood drain, Constrict, Grab, lunge, poison, pull, Trample, and Web. You don't gain full immunity to mind-affecting effects, but you do gain a +4 bonus on all saving throws against such effects.
  Tiny vermin: If you take the form of a Tiny vermin, you gain a +4 size bonus to your Dexterity, a -2 penalty to your Strength, and a +1 Natural Armor Bonus.
  Large vermin: If you take the form of a Large vermin, you gain a +4 size bonus to your Strength, a -2 penalty to your Dexterity, and a +5 Natural Armor Bonus.