Tight Dome Syndrome

Artist: So, what do you think?
Blue: Oh, um...Master will love it.
Artist: I'm was just worried, you see.
Blue: How so?
Artist: Well, I heard this year's cake would be blue, and--
Blue: Blue? I'm honored!
Artist: No, I mean, if I'd colored the cake blue...
Blue: Yes, I completely understand. I'm so wonderful, that you don't want to risk increasing my inner cranial pressure.
Artist: Tight Dome Syndrome can be painful.
Blue: Yes, and no one wants a swollen head. Not even a Dalek. It's ever so unbecoming.