This is a guessing game. I'll think of something to be,.. you can only ask me yes or no questions,.. and I'll give you clues as to who or what it might be. :) Whoever guesses correctly can go next. 
Alright, the first clue is that:
I can either be big or small. :)
Alright, the first clue is that:
I can either be big or small. :)