Rahne Sinclair aka Wolfsbane
Power: Through an act of will, she can transform into a wolf.
This may be my own opinion but I think Rahne likes to joke around. She doesn't mind using her powers for the fun of it. That includes playing frisbee and changing into wolf form to catch it.
Unlike Magman and Jubilee she hasn't flirted with any of the new ones. She probably would rather have them as friends then anything else.