Answer:
Long and slinky like a trout, never sings till it's guts come out.
I am nothing really at all, Yet I am easily foundΝΎ Ignore me at your own peril, and you might end up crowned!
They have not flesh, nor feathers, nor scales, nor bone. Yet they have fingers and thumbs of their own. What are they?
I open wide and tight I shut, Sharp am I and paper-cut fingers too, so do take care, I'm good and bad, so best beware.
A time when they're green. A time when they're brown. But both of these times, cause me to frown. But just in between, for a very short while. They're perfect and yellow. And cause me to smile.
Why was the cook arrested?