I think that if you are the last player standing in mob arena you should get 1-2 grass blocks. An alternative could be getting 5 grass blocks if you beat the final boss/wave in mob arena.
Neutral, I wouldn't mind this but like you are being given various items as prizes, most of which are worth at least 1 grass
I liked when mob arena gave out a variety of good items not items that you would never use but the last prize is fine for now
