D&D Monsters: Sphinxes

The sphinx is a creature of Greek myth, taking the form of a winged lion with a human face. In the original myths, she is, like the minotaur and many others, a unique creature, and appears most famously in the story of Oedipus. 

Confusingly, however, the term was retrospectively employed (possibly by the Greeks themselves) to also refer to the wingless lion-bodied statues of Ancient Egypt. These aren't the same thing as the Greek monster, and it isn't known what the Egyptians actually called them. They were usually, but not always, male and, judging from the statuary, were probably perceived as good and noble beings, unlike the much more hostile Greek creation. 

It seems to be the case that, in D&D, the male or "androsphinx" was based largely on the Egyptian creature (albeit with the addition of wings), while the female or "gynosphinx" has closer links with the Greek version.

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1E

As originally portrayed in 1E, sphinxes take the general physical form of the Greek monster. That is to say, they have the body of a lion with a humanoid head and a pair of birdlike wings rising from behind the shoulders of the forelimbs. The head of the male is not entirely human-like, having heavy brow ridges, an enlarged nose, and projecting canine teeth more reminiscent of some of the less dramatic sabretooth cats than of lions. They also have a distinct 'mane', with long hair and beard, but no moustache, and furred and rounded ears projecting from near the top of the head.

The females are noticeably more humanoid. For a start, the face and head are indistinguishable from those of humans, so far as we can tell, lacking the brows, fangs, and leonine ears. Furthermore, the shoulders and chest are also human, which they aren't on the androsphinx, which, among other things, means that the fur on the forelimbs does not appear to be continuous with that on the body.

Sphinxes are remarkably powerful beings. The male version has more hit dice than a red dragon, and is harder to injure in the first place. Since it isn't visibly armoured, and it seems unlikely that it's much more agile and skilled at avoiding blows, this must surely be some sort of magical resistance that prevents injury. Furthermore, if we look at the damage inflicted by the sphinx's claws, it also seems to be much stronger than even the largest of dragons which (since it's large, but not that large) also seems to imply some sort of magical boost.

True, the females are much weaker than the males, but they still compare favourably with a green dragon - the mid-sized species - if you just account for physical prowess and not the breath weapon. Both sexes are more intelligent than humans, with the females being close to the human maximum. It's also notable that the females are less honourable and more greedy than the males which, in this case, may well be because that's the way the original (female) sphinx was portrayed in Greek myth rather than being a more general commentary on the fairer sex.

The 2E version of the androsphinx has a more human-like face, but is otherwise similar to the previous version; the detailed appearance of the females is not given. Although they don't make it into the 5E core rulebooks, it's worth noting that earlier editions added two additional forms of male sphinx beyond the regular androsphinx. They all appear to be the same species, and it's only 2E that gives any real indication of how they are related to one another, although how well this system would work in reality is debatable.

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3E

The 3E sphinx is smaller than those described in the first two editions. Previously, they were almost as tall as an Asian elephant, and, given the different shape, must logically have been quite a bit longer. The stated body length, and the weight of 800 lbs (360 kg), given in 3E fit with something about the size of a rhinoceros - which is much shorter than an elephant.

As is common with other creatures in the 3E Monster Manual, the sphinx's head is also less humanoid than before, something that's particularly notable in the female example shown. She has a sloping forehead with a flat and broad nose, with the jaw projecting forward and containing teeth that are distinctly cat-like. The ears are much further back on the skull and, like the 1E (but not 2E) androsphinx, are erect, rounded, and furred. Her chest remains humanoid, although it's covered in fur, which it clearly wasn't in 1E, and there is probably also fur on the shoulders.

Of course, with the great inflation in the power of dragons, sphinxes are no longer a physical match for them. In fact, the gynosphinx turns out to have a lower strength than a regular lion, although her claws do similar damage; perhaps they are sharper. Otherwise, their statistics are roughly what they appeared to be previously, including the very high natural intelligence. Previously solitary, we're told that female sphinxes sometimes live in groups of up to five, perhaps because female offspring remain with their mothers for longer than males.

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5E

The move away from a humanoid appearance continues in 5E, to the point that sphinxes are now essentially just winged lions. The head is, however, not entirely leonine, having a shorter snout and, in the case of the female, a mane with a similar pattern to human hair. But nobody would describe it as human-like... other than the author of the accompanying text descriptions, anyway.

The 5E sphinx is also more clearly a magical being than those described in editions prior to 4E. Now, they are immortal creations of the gods, not living beings propagating by reproduction, as the earlier versions very clearly were. They also have many more magical abilities, and have the resistance to regular damage that's common for semi-divine entities, along with immunity to many other effects that worked normally on those in earlier editions. It's notable that the sphinxes in this edition wear decorative jewellery and other adornments - how they put these on and maintain them is unclear, given their absence of opposable thumbs...

Aside from the males having supernaturally high charisma, most of the detailed stats change little, other than the usual "more hit points but less armour" typical of 5E. Unusually, they retain their unique language rather than speaking (say) Celestial.

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From 4E onwards, sphinxes are semi-divine entities created to guard sacred treasure. They clearly have a physical/organic form, and even register as magical animals (rather than celestials) to the relevant spells, but, so far as we can tell, they do not reproduce as animals do, and are apparently immortal. In earlier editions, however, they are clearly just rare, but unusual, intelligent creatures tied to the mundane world.

We’re told in the first two editions that male sphinxes try to avoid the females, but that the reverse is not true. This is, as we might expect, a different setup to that seen in real-world animals. Mammals that live solitary lives, as sphinxes do, have their own territories, whether clearly demarcated or otherwise, from which they exclude members of their own sex. But they do typically overlap the territories of the opposite sex and for obvious reasons. They may ignore opposite sex individuals outside of the breeding season, and stay apart from them as much as they can, but they do not actively avoid them. Sphinxes, or at least the males, apparently do just this.

This implies what could be described as weakly polyandrous mating system. Polyandry occurs when a single female mates with as many males as she can, but the male does not do the reverse. It’s common among insects (think honeybees) but rare among mammals – some examples do exist, such as marmosets, but their social life is very different from that of sphinxes. We can also say that it’s ‘weakly’ polyandrous because the rarity of sphinxes means that, in practice, it’s going to be hard for any gynosphinx to find multiple males to mate with, no matter how much she’d like to, so that, in practice, they’re likely to end up with serial monogamy.

At any rate, this setup does raise a few questions. For one, the gynosphinx must overcome her partner’s reluctance to associate with her somehow. Magical enchantment seems unlikely, given what we know of the creatures, but simple pheromones may well do the trick.

The second, and harder question, concerns the sphinxes’ sexual dimorphism. Sphinxes are among a relatively small number of D&D creatures (at least, post the 1E versions of the evil humanoids) where the males are sufficiently different from the females for the two sexes to have separate stats. Indeed, the physical differences (and to a lesser extent, mental and cultural) between them are really quite dramatic.

Obviously, this is true of many real-world animals, from lions and deer to gorillas. But in these animals, the males are larger because they are polygynous, and compete with one another for mates. With sphinxes, it’s the females that compete, so they should be the larger or more magically powerful – but they’re not. Even if we take serial monogamy as the practical outcome of the mating system and argue that gynosphinxes do not, in practice, get the opportunity to compete with one another for mates very often, the two sexes should be similar, as tends to be the case for monogamous species.

Which may perhaps be due to a divine, rather than evolutionary, origin. We could also question why it is that the signature power of the sphinx – its devastating roar – is possessed only by the males, and not the females. It’s clearly magical, so there’s nothing that would clearly prevent females from possessing it, and being smaller, and less well-defended in other respects, you’d think it would be more useful to them. One possible explanation here is that, while the roar is boosted magically, it requires a larger lung capacity to initiate it, and the gynosphinxes aren’t big enough. But it’s a stretch.

How loud is a sphinx’s roar?

One problem in answering this is that ‘loud’ isn’t really a proper scientific term, and can mean different things in different contexts. But, if we use the decibel as our yardstick, we can be surprisingly precise about the sound level of an androsphinx’s roar: it’s just over 190 dB.

How can we be so precise? Because, as it turns out, the maximum possible sound level in an Earthlike atmosphere at sea level is 194 dB. That drops with altitude, and can even change with the weather, and it doesn’t apply underwater (in fact, the underwater decibel has a different definition from the air-based one and isn’t directly comparable). The reason for this is that the sound pressure level, which is what the decibel is actually measuring, can’t exceed the atmospheric pressure of the gas the sound is travelling through. This is the loudest sound it’s possible to make, and the androsphinx can definitely make it.

But it is perfectly possible to put more power into making a sound than would be required to hit the 190+ dB limit. Where does the extra energy go if you do this? It creates a shockwave, and that can be almost arbitrarily powerful. (Which is why, in a sense, an atomic bomb or a volcanic explosion is ‘louder’ than, say, a hand grenade, despite both having the same sound pressure level). The resulting shockwave, depending how powerful it is can… well, knock things over, crack stone, and so on.

Which is exactly what the androsphinx does.