I am Sweet

What five-letter word becomes shorter if you add two letters to it?

I am the fifth planet from the sun.

I am the fastest spinning planet in the solar system.

Who am I?

I eat other animals. I have a big mouth.

I am green. I live in water.

Who I am?

I am the seventh planet from the sun.

I have 27 moons. My nick name is "Ice Giant".

Who am I?

I am small. I can be scary.

I have eight legs. I spin a web.

Who I am?