Random Riddle: 7-16-2015

I’m the smallest of my kind, no doubt about that;
Compared to my brothers, I seem like a rat.

A blue face have I, a blue face, you know;
It’s awfully cold here, with poisonous snow.

My name came from a god, a god with great might;
Although you know of me, I’m way out of your sight.

What am I?
 

Riddle