Well THIS is an Interesting Question.

New blogger Wince and Nod asks:

Sofia Sideshow commented a while back about how a shotgun is Hollywood's weapon of choice when it comes to dealing with monsters. I wonder what Rachel Lucas, Kim du Toit or Kevin Baker at The Smallest Minority would have to say about this.

This is reminiscent of the oft-recurring question "What caliber is best for defeating flesh-eating zombies?" that somebody brings up on AR15.com at least once every two or three months.

Sofia Sideshow's site puts it this way:

Shotguns are also good demon-killing tools. Shotguns are really the action-movie Leatherman. They're so useful. Aliens, Terminators, Demons, Raptors...whoever grabs the shotgun at the "we better grab some weapons" part of a movie usually lives.

To go along with that, I've got a quotation archived by a "K.R. Murphy":

"There are precious few horror films that couldn't be cut well short by a single loaded 12 gauge and someone with the sense to use it."

Truer words...

"I like to keep this handy," Click-CLACK! "for Close Encounters." - Michael Biehn as Corporal Hicks,
with his (short-barrelled!) Ithaca Model 37 from Aliens

(In the absence of any evidence tending to show that possession or use of a "shotgun having a barrel of less than eighteen inches in length" at this time has some reasonable relationship to the preservation or efficiency of a well regulated militia, we cannot say that the Second Amendment guarantees the right to keep and bear such an instrument. Certainly it is not within judicial notice that this weapon is any part of the ordinary military equipment or that its use could contribute to the common defense.)

Sorry, just had to throw that in.

"This... is my BOOM STICK! It's a twelve gauge double barreled
Remington, S-Mart's top-of-the-line. You can find this in the
sporting goods department. That's right this sweet baby was made in
Grand Rapids Michigan. Retails for about $109.95. It's got a walnut
stock, cobalt blue steel and a hair trigger. That's right. Shop
Smart. Shop S-mart"
Bruce Campbell as Ash from Army of Darkness

Just a couple of examples.

Shotguns are quite effective defensive weapons. That's one reason that police cruisers were for years equipped with a riot gun. Nothing gets someone's attention quite like racking the slide on a pump-action, and very little else makes as much an impression as 12 .33 caliber 00 buckshot pellets from a 12 gauge shell, or a 1-1/8 ounce slug.

At close range, the shotgun is a devastating weapon, even against the undead! No demon will remain unaffected after receiving the contents of both barrels of a boomstick, no zombie will be munching on your brain after you've removed his lower jaw with a well-aimed blast of buck, and even though you risk getting splashed with blood with a pH of zero, no alien exoskeleton will withstand a point-blank impact of a slug.

Of course, not too much is effective against the polymer alloy of a T-1000 Terminator, but a shotgun at least slows one down - more than a 9mm Europellet anyway.

I think the defensive shotgun is an excellent choice against goblins of all types, which is one reason I own one of these:

Mossberg 590

But mine has the Speedfeed stock that holds four spare rounds. Magazine capacity: Nine rounds of 2-3/4" shells. Barrel: 20", evil baby-killing heatshield, and (gasp!) bayonet lug for the M-9 bayonet. I keep a box of #4 buck (25 .24 caliber pellets) for mine, and a couple of slugs in the stock just in case I need to stop a charging rhino. Or demon.

Thanks for asking.