Wolf Form

Take the shape of a wolf: low to the ground, faster than a man, with night vision. Jump at someone nearby to dive at them (Wolf Lunge) and right-click to stampede (Wolf Stampede). In a fight, press the key again to change back. Out of combat the shape holds as long as you like, its timer only running down while you fight; there, pressing the key again changes you back and pressing another form's key changes you straight into that one, both for free.