What Comes Once, Twice and Never

Which 3-letter word can be inserted into all four lines above to form complete words?

P_ _ _ N T

D E _ _ _ S T

S T _ _ _

C _ _ _ E R

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?

I am white. I have a brown thin skin. I grow in the ground.

I am a root vegetable. When you cut me, I can make you cry.

Who am I?

I am in the kitchen. I have lots of food inside me.

I keep food cold.

What I am?