If you have a problem with "entitled DMs" (whatever that even means),
"Viking-hat" is a term I've heard used on forums, though I've only heard it used in a third-party way (e.g. speaking about people that aren't actually involved in the conversation). I, personally, would also think a DM is "entitled" when they make lengthy and sweeping declarations of what's not allowed in their games--there's this way of presenting it, I don't know how or why, that just makes it sound so
gleeful, like the DM is just SO HAPPY to be able to say "no, hell no, and never darken my door again!" to players who simply find something interesting/enjoyable/etc. and express genuine enthusiasm about it. "You can't play
this in my games and
that is out because they're *ALWAYS* evil and I don't allow evil characters.
Those are banned in all forms, and if you want to play
them then you can't have any of
these options. And if you come to the table with a character sheet that has any of these things because I forgot some of them, you have to make a new character." I've had people more-or-less straight up say exactly that--just with a *much* longer list of restrictions, bans, and pigeonholes.
(You also have DMs who do things like set the players up for a fall by consistently implying that a situation is other than what it is, and then rip the rug out from under the players at the last second and laugh--whether internally or externally--when the players fall for it. That might be going a step further than
just "entitled" though.)
Another way to put it: the "entitled" DM is the autocrat who wants to make sure you
know he's the autocrat, perhaps even one who occasionally exercises power purely to demonstrate that he has that power.
why are you playing with them?
He may not be--simply knowing they exist, just as you know that "entitled" players exist, is enough.
I humbly recommend playing the way you like, with like-minded individuals.
I have gotten lucky with most of my DMs--but having followed enough forum discussions, I can
guarantee you that they exist--and it is not always possible to play with someone who isn't like that. It may not even be obvious that they
are such a DM until you're already invested in the game, at which point it ceases to be just a "bad gaming vs. no gaming" situation, with all the attachments and obligations that arise due to gaming being a social activity. In my own case, for example--if my 4e DM suddenly demonstrated a huge entitled streak, I'd be between a rock and a hard place, as I'm the only heavily-armored character. My departure could mean ending *everyone's* fun, e.g. causing the campaign to fold, and I don't want to be That Guy who flips the table just because somebody else is getting on my nerves. (I'll note that I think this is
fantastically unlikely, and that my DM seems like a great guy who really cares about making a mutually-fun experience. This hypothetical is just to demonstrate that, once you *start* gaming, attachments accrue.)