So you’re a Yog-Sothoth-worshipping cult fanatic, but you also care about your family. You want to bring forth a presence of an Elder God, since they technically came here long before us, but you don’t want to lay scourge to all the lands on the green earth. Can you have your own pet Dunwich Horror like Wilbur Whateley did in 1928?

The Dunwich Horror is a pretty big Betsey. In Lovecraft’s work of the same name, swaths of trees 30 ft across are completely flattened. Although the monstrosity is only glimpsed temporarily, we get enough of an image to know it is an oblate spheroid on many legs with scores of mouth-bearing tentacles sliming all over the place. To establish whether this pretty Petunia can coexist with humanity, we need to make some estimates of its size and mass.

If we assume it is a sphere of 30 ft diameter (9.1 m), we get a volume of

V = 4/3 * Pi * (9.1 m /2 )^3 = 395 cubic meters.

If we also assume that tentacles protrude from half the surface out to a length of say, 10 ft (3.08 m), then we get the volume of the tentacles:

V= 4*Pi * (9.1 m /2 )^2 / 2 *3.08 = 400 cubic meters.

Therefore the total volume of the Dunwich Horror is roughly 800 cubic meters. If we take its density to be close to that of water (and ignore any part of it wrapped up in other dimensions) then we get 800,000 kg for its mass, or 800 metric tonnes.

An accepted biomass assumption is that 10% of a prey’s mass is converted into mass in the predator. If we assume linear growth over its lifespan of roughly twenty years, 8,000 metric tonnes of mass must be fed to the Dunwich Horror.

What sort of biomass is available in Dunwich? Well, first, we have to know where Dunwich is. A man named Geoffrey has done an incredible job detailing the closest real-life location to the fictional Dunwich: the town of Shutesbury, Massachusetts. Appropriately its original name was Road Town, since it was a town between towns, not really a place worth stopping. It’s similar to the way Lovecraft describes Dunwich.

Shutesbury’s population had declined to 222 in 1930, around the time of the Dunwich Horror’s peak. Nowadays, it has 1800 people. Since that first Dunwich attempt didn’t go over well for the balance of the universe, let’s assume we’re living in modern-day Dunwich (Shutesbury). The town itself occupies 70 square kilometers.

Hopefully we don’t have to feed the Dunwich Horror purely human meat (although I hear some of them can be picky). What wildlife and domestic animals would sate our cute Kirby’s appetite?

There are 850 moose, 39,000 cows, and 2,000 bears in the State of Massachusetts. We’ll ignore smaller mammals since the Dunwich horror, as much as we’d like to focus on its positive aspects, is probably an apex predator. Massachusetts has 27, 336 square kilometers, and if we assume a uniform distribution of animals over the entire state, that gives us 2 moose, 100 cows, and 5 black bears in the Dunwich region. Let’s not forget about the white-tailed deer, which have a density of 6 per square kilometer in the Dunwich region. That gives us 420 white-tailed deer, a substantial fraction of the wildlife biomass in Dunwich.

The average masses of the above animals are :

Since we’re shooting for a stable population, we want the proportions to not diminish substantially. Black bears reproduce at a rate of maybe 2 / year / bear, which would give us 200 bears over the growth period of the Dunwich Horror, or 36,000 kg. It’s a decent start to a budding abomination.

Deer mature in 2 or 3 years, then reproduce at a rate of one per year for the next ten years. If we assume half the deer population reproduces over the full duration of the twenty-year period, we get 4200 deer with a total mass of 1,260 tonnes. Little DH is on its way to a healthy lifestyle.

If we assume similar reproductive rates for moose and cows, then we get a mass of 11,000 kg and 750 tonnes, respectively. The grand total is therefore **2057 tonnes**, still 6,000 tonnes short of the quota. By any measure, that’s a lot of meat. No wonder poor Wilbur had to import his sacrifices and look to the Necronomicon for guidance.

Uh oh. Looks like it’s time for human sacrifice.

1800 people in Dunwich reproduce, so there may be enough action going around to fill in the DH’s musculature.

The fertility versus death rate in Massachusetts yields a net growth of 4.5%. However, the people of Dunwich are described as thoroughly inbred. Studies have shown that mortality rate could possibly be increased by 60% in inbred populations. This brings our net growth down to 4.07%.

If we calculate by the mystical and impossible-to-comprehend-Cthulhu-like compound interest, we get a final population of 4,000 at the end of twenty years. Assuming all 2200 people were devoured by our friendly neighbourhood horror at a mass of 60 kg each, we get a mass of 132 tonnes. Still quite a way’s off of the required 6,000 extra.

OK, so maybe you can’t raise your own Dunwich Horror without decimating life as you know it in the region. But what if you outsource the destruction? Convince someone else to raise the beast until it was a healthy, well-balanced symbol of cosmic destruction? Could you then maintain the Dunwich Horror at its 30 ft size?

If we calculate the Basal Metabolic Rate (minimum number of daily calories to sustain life) of the Dunwich Horror as if it were one of our own (i.e human) using the Mifflin St. Jeor equation, we get 8,000 kcal / day. Over a period of a year, this is 2.92 gigacalories. Meat contains 2.5 kcal per kg, so we’d need 1168 tonnes per year, half of what we’ve determined the Dunwich biomass growth can sustain* over 20 years.* The litttle beastie requires a bit too much protein for the little town of Dunwich (Shutesbury), unfortunately.

In conclusion, the next time you’re considering calling forth a child of Yog-Sothoth to pave the way for Hell on earth and the return of the planet to the rightful Elder God rulers, think about the ramifications, and whether or not it will fit the vision of a sustainable earth you want for your goatspawn children.