What Am I Riddles

Question: Looking at my face, I'm no more than six.
Look at the rest of me and I'm 21.
You'll see my twin and me in Las Vegas.
Say my name and you'd be uttering a threat.

What am I?

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?