Cleon
Legend
Spring Attack and a +2 enhancement bonus (splitting the difference?). Would that do it?
I'm also inclined to give it a higher speed since an animated object with wheels has a higher speed than one with legs and they're described as rolling around.
How about:
Pinwheel: Pinwheel Origami have Speed: 40 ft. (8 squares). They attack by slashing with the blades of their 'wheel', which have the attack properties of a +2 kukri +X melee (1d4+4/18-20). Pinwheels normally slash at an opponent's legs as they roll past them. They have Run and Spring Attack as bonus feats.