As is, seems situational, since its cost is somewhat high for an early game card (you'd want this card out before they could even play any shields), which means it might end up being a dead card since it can't deal with the shield they have at the moment.
So yeah, making it a creature that continually removes shields would be nice.
Also, perhaps it could that it automatically destroys the shield upon play, then has an ability like "
: Destroy opponent's shield", since I suppose a Pulvy (albeit restricted) with no ability cost would be rather powerful (especially since it's not even a weapon and doesn't require a duo).