I am Made with Cream

I am the eighth planet from the Sun. My twin brother is Uranus.

I am the farthest planet from the Sun.

I am small and brown. I eat nuts.

I can climb trees. I have a nice tail.

Who am I?

What has one eye but can’t see?

Where does Friday come before Thursday?

Guess what comes next in the sequence:

1 2 3 4 5 ? 

The answer is not 6. What is the answer?