After seven years on '30 Rock', Jack McBrayer's seen the true colours of his co-stars -- and as you might expect, it's not always pretty. What's it like on set when Alec Baldwin or Tracy Morgan is having an off day?
In this clip, Jack talks about...
Working with Alec Baldwin
"After seven years it's less intimidating, but you always know when to steer clear."
On Tracy Morgan
"Tracy never gets angry -- he's just a crazy person."