What Am I Riddles

Question: What can you smell but not see. And can be deadly, too.

Question: I live in water, but not in the same place. Sometimes it’s drinkable and other times it's not. I am either a hunter or gatherer. I am known for being gentle and easy, but I don’t live long. You will know me by my large eyes and goofy lips. People know me by my slimy body. I can be found in your house or out in the wild but never in between. I am friendly so I will likely be your friend in school. What am I?

Question: he is a king who's good at measuring stuff.

Question: I am made throughout the world, I am a masterpiece. And to your ears, I am but a humble feast. I am but a traveler, depicted through paper as a start, I can even be made through the work of your heart. What am I?

Question: A man travels by wagon,
brings joy each evening,
but depression by the morning.

Who is he?