Answer:
In the night a mountain, in the morning a meadow.
The man who made it didn't need it. The man who bought it didn't use it. The man who used it didn't want it.
Round like a dishpan and smaller than a bathtub. But the ocean can't fill it. What is it?
Hard to catch, easy to hold. Can't be seen, unless it's cold.
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
What is so fragile that saying its name breaks it?
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?