D&D Monsters: Giant and Phase Spiders

The first edition of AD&D includes a number of giant invertebrates, mostly insects. The idea behind these may be influenced by the "big bug" films of the post-WWII era, starting with Them! in 1954, and they provide the possibility of exotic-looking monsters that nonetheless have to look no further than the natural world for inspiration. 

Once we leave insects and look at spiders, there is an even more obvious inspiration: Shelob in Lord of the Rings. While she, and her relatives in other Tolkien works, were likely the primary inspiration behind the original giant spiders of D&D, there are plenty of other fictional examples. The cinematic classic The Giant Spider Invasion is one such (yes, I've actually seen it; there's 80+ minutes of my life I'm not getting back...) and, from more modern fiction, there's Aragog in the Harry Potter books. Giant spiders aren't found in European myth, but there are the Tsuchi-gumo of Japan, which are usually described as spiders (but sometimes crickets) and, at a stretch, Anansi the spider-god of West Africa.

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1E

There are no less than five kinds of monstrous spider in the 1E Monster Manual, and they're surprisingly varied. The basic hit dice show the usual stepwise progression that subtypes of a particular monster tend to in 1E, but this does not apply to their other attributes. For instance, the phase spider is the largest of the five forms but does not also have the toughest exoskeleton, while the second-smallest form is the fastest, hunting like a wolf spider and not spinning webs.

Only the two smallest examples are really described as wild animals, with the smallest in particular seemingly inspired by the Mirkwood spiders of The Hobbit. The other three do have at least some degree of intelligence, although there's no indication that they have any kind of language of culture. The second-largest, simply called a "giant spider", is the one most clearly based on Shelob, being described as actively evil rather than just hungry. 

Monstrous spiders are said to live in every clime except the coldest and in every available habitat type; likely there are multiple different species even within a given size category. Although it's arguable from the illustration, they're presumably intended to physically resemble regular spiders, apart from the size.

Most of these spiders change little in 2E, but the phase spider is an exception. Originally, it's supposed to be almost impossible to distinguish these from a particularly large "giant" spider, but the text and illustration in the Monstrous Manual make it appear something else entirely. Bizarrely, it has ten legs, one pair of which seem to be modified as antenna-like sensory organs (this latter feature is not seen in real-world spiders, although it is in some other arachnids). It has a humanoid head and neck, albeit with arachnid palps, and finger-like claws on the front pair of limbs. The abdomen has a series of segmented plates on the upper surface, a feature seen only in a few primitive species in the real world, of which the best known is probably the Kimura spider of Japan.

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3E

This edition has an even greater array of spiders, arranged by size and whether or not they spin webs, rather than being solitary hunters or 'trapdoor' spiders. Since they live almost anywhere, it's plausible, once again, that this resembles an array of different species. However, since we're not told otherwise, and there isn't much other differentiation between them, it's possible that at least some giant spiders grow throughout their life, only limited by the size of the available food supply. While the smallest (newborn?) ones are about the size of a cat, the largest are over 60 feet (20 metres) across, which is... impressive.

Perhaps the key difference from earlier editions is that all of the 'regular' monstrous spiders have zero intelligence, which, in game terms, means that they're immune to mind-affecting magic. But it also means that the intelligent, Shelob-like, giant spiders of the earlier editions no longer exist; they're all just animalistic now.

The exception are the phase spiders, which retain their (admittedly low) intelligence from earlier editions. They are specifically stated not to speak, however, so this likely reflects no more than animal cunning, related to their unusual hunting tactics. Physically, phase spiders are back to looking like regular spiders, although they do have some notable differences from the real-world versions, which I'll address below. They no longer spin webs which, when you think about it, would have made their phasing ability rather less useful than it is for something that actively hunts.

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5E

After steadily multiplying in the earlier editions, the regular "giant spider" is reduced to just a single form here (in part, perhaps, because the idea of adjustable templates has gone in this edition). The creature described is roughly horse-sized, making it similar to the largest form in 1E, and has the intelligence of a typical, mammalian, animal such as a bear. Unsurprisingly, if you're just going to describe the one, it's a web-spinner, not a wolf spider.

The phase spider looks similar to its 3E counterpart, although the eyes are arranged differently. The only notable changes are due to alterations in the rules themselves, rather than the details of the thing they're describing.

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The general details of what a spider looks like are probably familiar to most people. Spiders are arachnids, members of a group of eight-legged arthropods that also includes scorpions, ticks, and mites, along with some lesser-known creatures, such as solifugids. Their body is divided into two portions, the cephalothorax to which the limbs are attached and which also includes the eyes and mouth, and an abdomen behind it.

Everyone knows that spiders have eight legs, although some seem not have noticed that they also have a pair of short 'arms' - technically called pedipalps - that sit in front of the legs and don't reach the ground. These are used by the spider to feel what's in front of it, and also contain organs of taste and smell (after all, they don't have a tongue). Most spiders have tooth-like structures near the base of their pedipalps to help grind up food before they eat it, while males also have their genitals on the end. Between the pedipalps lie the fangs, with a toothless sucking mouth just behind them.

Crucially, unlike insects, arachnids do not have mandibles.

The spiders in the 4E Monster Manual fit this description fairly well, looking like actual arachnids but, whether intentionally or otherwise (after all, they're fictional) those in the other editions do not. Most obvious here are the phase spiders, which entirely lack pedipalps in both the 3E and 5E illustrations. To be even more picky, both illustrations, and that of the 5E giant spider, lack a short segment found on the knees of a real spider. The 5E phase spider also has a hook-like claw on the inner edge of the ankle and what should be the final two segments of the leg are merged into a single stabbing spike that must make it really difficult to walk. (The foot of real spiders is typically flatter, and bears two or three claws on the end... it would likely have to be larger still to support a heavy body weight).

Spiders usually have eight eyes, and the D&D illustrations typically show this. The two eyes in the centre are the most important and are often larger than the others, and this is especially true in hunting spiders that don't weave webs and require decent binocular vision to locate their prey. This is clearly the case for the 3E phase spider (which also seems to have pupils, which real spiders don't) but not so much in the 5E one, which may be less visually oriented.

Although most other spiders are clearly not blind, they rely much more on feeling vibrations in their web and on sniffing out their prey. They also have hairs on their legs that effectively function as ears since they can sense the vibrations in the air caused by, say, a buzzing fly. In some spiders, their other senses are good enough that they could be argued to have a real form of  'darkvision', since they can find and kill prey without any light. (Such spiders are often completely missing the main pair of eyes, leaving them with only six).

The cephalothorax of spiders is mostly occupied by the brain and the muscles that move the legs, but it also includes the stomach and, of course, the venom glands. The heart is a long tube running along the top of the abdomen, which otherwise contains the intestines, kidneys, silk-producing glands, gonads, and a pair of lungs.

The latter are significant because lungs scale up to large size rather better than the tracheal system of insects does. Most spiders actually have trachea as well as lungs, but tarantulas (and a few others) have a second pair of lungs where the tracheae would otherwise be, and presumably the same would be true of giant forms. This makes it far more plausible that they could become massive, although, in reality, the exoskeleton would still limit their size, as I previously discussed for ankhegs. For what it's worth, a spider's nostrils are near the front of the underside of the abdomen, and nowhere near where we might expect its nose to be if it had one.

While there's quite a lot that can be said about how spiders have sex, this isn't directly relevant here. (Although it's a myth that the male is always eaten afterwards; some species will do this if the female is hungry enough, but most don't try at all). What does matter is that they lay multiple eggs, which they wrap in silk to protect them. Many real-world spiders protect the eggs until they hatch, guarding them in a silk-lined nest or the like, and some continue to care for their young afterwards - a few go as far as to provide regurgitated food for them, as birds do for their chicks. 

Baby spiderlings look like miniature versions of the adult, although they aren't usually born with functional venom or silk glands, are almost blind, and can't initially move about much. Like other arthropods, they have to repeatedly shed their exoskeleton as they grow, leaving husks behind.

This brings us to the obvious issue of the webs. Spider silk is produced from organs at the end of the abdomen and can be used to create a wide range of different webs. Of these, the orb web is the one we immediately think of when we draw a spider-web: radiating spokes with a spiral of sticky fibres running out from close to the centre. Most others are variants on this theme, forming funnels and so on, but there are a couple of more drastic alternatives, including the classic 'cobweb' formed of seemingly random tangle lines. 

What a real spider does once its prey has become caught in the web actually varies quite a bit. Most orb-weaving spiders, however, wrap their target up in silk to immobilise it before stabbing their fangs into the body to paralyse or kill it. They then haul it to the centre of their web, and inject it with digestive juices, chewing up whatever solid bits remain with the "teeth" on the pedipalps and then sucking up the resulting liquid and smaller chunks.

A giant spider might have an easier time of this than a regular one since so much of their prey surely consists of unarmoured vertebrates rather than insects with exoskeletons. Either way, what you're likely to be left with is a bundle of chewed up bones and indigestible bits that were too large for the toothless sucking mouth to slurp up. 

In 5E, giant spiders can also throw their webs at the targets, projecting them at least six times their own body length. Needless to say, no real-world spider can do anything of the sort, and, indeed it's hard to see how they would, given that the silk comes out of the rear end and, not having a neck, a spider has no means of seeing what's behind it. The closest we get are some hunting spiders that make a small web, pick it up with their front legs, hold it outstretched, and rush at their prey to physically push it onto them and then use as a hand-held net.

Although 5E phase spiders are said to be good at climbing through webbing, neither they, nor the 3E version, seem to use webs themselves, instead hunting for prey like more typical predators. Several real spiders, including tarantulas, do exactly this - they can still produce silk, but it isn't sticky and is only used to protect the eggs, not to catch prey.

The phase spider's signature ability is a rabbit-hole of its own that is probably better dealt with elsewhere. I'll just note that while it works in much the same way in all the editions, it doesn't recharge as quickly in 5E, making it easier to fight the creature without the aid of rare and impressive magic.

[Photo by JJ Harrison, from Wikimedia Commons.]