Answer:
They are toothy nocturnal immortals.
One strand dangles. Two strands twist. Three or more can fashion this.
You row in one while you float.
What can be seen but not touched?
Once you know it exists, it no longer exists. What is it?
As round as an apple. As deep as a cup. All the king's horses can't pull it up.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?