Well,seeing how Usopp has turned into a summoner(I think thats what it's called),and Oda loves animals,I'm predicting more animal-shaped plant finishers.And cause I'm still recovering form the epicness that is the Impact Wolf,I can't wait to see more!
I think it'll be cool if the Impact Wolf could move on it's own,to an extent.Like,even if it misses,it can still 'run' at it's target,or Usopp diliberatly shoots it away from the enemy to fool them.Like,why shaped like an animal?Just to look cool?Maybe,but I'm hoping theres more to it.
I'm guessing theres going to be a kabuto and a hercalues shaped plant summons,for obvious reasons.
Or maybe:
Forest God :ninja: