How do I stop feeling intimidated by my advisor? Whenever I meet my advisor and interact with him, in class or otherwise, I can't help feeling intimidated. I feel scared of the fact that I may fall below his expectations, and I become tongue-tied and mind frozen even though I know stuff. 

How can I avoid this? Is this common at this stage? (I am an undergrad and just beginning research.)
I think this is a typical syndrome for young students, or those students who have massive respect for their Professors or Teachers. 

Usually the students consider their Professors to be superior to them; In addition to this the student might have some expectations in the future from that guide, trying to impress him all the time, so he is rewarded later on.

The way to solve this is to have more communication with that person and after all realize that he is a regular human being, who sometimes in the past used to be a student, and most probably was intimidated by his guide. 

As you get to talk interact with your guide the Myth that you have in your head about him/her will start to get into the frames of normality, and the intimidation will go away after a while.

Long story short: he is a human being as well