Inspired by the Mister Doctor exchange in Doctor Strange. I figured it would be even funnier in this fandom (which I don't own). So, here's a little crack not-taken-seriously. Allons-y!
The villain of the week loomed over the Doctor, who was tied to the chair in an abandoned warehouse. "Any final words Mister-"
"Doctor."
"Mister Doctor?"
"No, I'm called the Doctor."
"Doctor who?"
"You wouldn't believe how many times I've been asked that. Just the Doctor."
"Okay, let's start this again. Any final words, The Doctor?"
"No, don't do that. Just call me 'Doctor.'"
"Wait, so you're a doctor?"
"Yes, and the Doctor. The 'the' is important."
"But you just told me not to call you The Doctor."
"Did I? What did I ask you to call me instead? I doubt John Smith has come up in this conversation."
"So that's your real name?"
"No!"
"Well then what is?"
"Oh, like I'm telling you."
"Of course you're not. Wait, do you have a PHD then?"
"Yes. Well, it depends on your definition of a PHD."
"A PHD is a PHD!"
"Not on some planets."
"What do you mean 'some planets!?'"
"Oh, I forgot to mention, I'm an alien!"
"A WHAT–"
"You heard me. Oh, by the way, I travel in time too."
"You're joking. You're pulling my leg, now I know you're lying."
"No, really, I'm over 900 years old and travel through time and space in an old fashioned police box that's bigger on the inside, going on wacky adventures everywhere and everywhen with my friends."
"Ohhhh! You're insane."
"Well, if you don't believe me, I can show you."
"Well, of course! All fun people are!"
This went on for quite a while, eventually leading to the Doctor talking the villain out of whatever evil they were doing because they're good at that sort of crap. They all live happily ever after. The end.