Answer:
Big as a biscuit, deep as a cup, but even a river can’t fill it up. What is it?
If you spot one of these eastern warriors, they're not doing their job right.
Talks like this, a green wise man does. Guess my clue, you will.
I am the greatest teacher out of them all, but alas in the end I kill my pupils.
Searing 'cross the pitch-black skies, I scream in celebration, Yet moments later, my outburst through, I am naught but imagination.
What is so fragile that saying its name breaks it?
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?