Answer:
A horrid monster hides from the day, with many legs and many eyes. With silver chains it catches prey. And eats it all before it dies. Yet in every cottage does it stay. And every castle beneath the sky.
What can provide food before it is alive, while it is alive and after it's dead?
My first is twice in apple but not once in tart. My second is in liver but not in heart. My third is in giant and also in ghost. Whole I'm best when I am toast.
Face with a tree, skin like the sea. A great beast I am. Yet vermin frightens me.
With four oars it swims but it is always at home. Its back is like armor, tougher than chrome. What is it?
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?