He is intimidated. Because, even though I didn't get a paycheck from google I'm as good or better than him. Not that I ever made it an issue but he's obviously traumatized by smarter colleagues/managers back in his career and he's looking for a payback at a second rate company.
You started off saying he's an ex-googler. His resume is probably pretty respectable? Someone with a good resume is likely not intimidated. This 'second rate company' could collapse tomorrow and he's really not worried. He'll find the next spot; so why be intimidated. I find the more senior engineers generally understand this.
You say he's egotistical. Egotistical people are never intimidated. So I'm curious by your contradiction.
>I'm as good or better than him.
You are comparing yourself to him as the rookie on the team? He has an immediate advantage of understanding the company's infrastructure from experience. You may well be better than him despite this huge disadvantage but that's not the problem. You should never compare yourself to others. You may only compare yourself to yourself of yesterday. Are you better off today than you were yesterday?
I'm curious, you're a rookie, where are you coming from? Presumably not google.
In your previous position(s) did you have someone similar?
Egotistic behavior is actually a response (most of the time unconscious) to being intimidated. Truly capable people are rarely egotistic. I am talking about people at the top of their game, like Field medalists, Nobel laureates..etc. I doubt his colleague is egotistic to a beggar, for example.