Dragons. We've come to the namesake of the game, and it shows, with 4 pages devoted to the critters - most of the monsters in OD&D get a single paragraph.
As far as Dragons go, I haven't used them a great deal since the early days when I was playing Mentzer Basic. I think I succumbed to the hype a bit, thinking of them as untouchably powerful until PCs hit high level. In OD&D they're just another monster, albeit one with an inordiante amount of space devoted to it. I'll be trying to use them more often when this campaign gets out of the planning stages.
The five classic evil dragons are featured (White, Black, Green, Blue, and Red), as well as Golden Dragons to represent for good.
The dragons all get their standard breath weapons: White a cone of cold, black a line of acid, green a cloud of chlorine gas, blue a bolt of lightning, Red and cone of fire, and gold with its funky combination of fire and chlorine gas. They can only breathe three times a day, and when they do is determined randomly (which I find weird for a supposedly intelligent being, but them's the rules). A dragon's breath weapon deals the same damage as the creature's hit point total, though it's a difficult rule to find. It cuts down on a few dice rolls at the table, but it makes me wonder if the breath weapon damage goes down as the dragon is wounded. I'm thinking not, but I'll probably defer to the answer held in AD&D, whatever that may be.
Dragon hit points are determined by size, rather than by rolling. You roll 1d6 to get the Dragon's age, and here we get our first taste of the Age Categories. There are six: Very Young, Young, Sub-Adult, Adult, Old, and Very Old. These categories remain into 3e, albeit with several more added and sandwiched in between. They even list age ranges in years here, and these are seriously out of whack with D&D dragon lore - Adult dragons are 26-75 years old! These numbers get higher as D&D goes on, and at the moment I can only explain it as dragons gradually learning to extend their lifespans magically. Or possibly the more recently hatched dragons have shorter lifespans then their mighty ancestors, and it's the current generation of dragons that are being slain by OD&D characters. So then the elder dragons awaken around 1e-time, and so on.
Not all dragons can speak, which is also a departure from the uber-masterminds that they seem to get played as these days. Each type has a percentage chance, and those that can talk then have a chance to cast spells. I like this - it gives an option of playing a straight non-spellcasting dragon, which is nigh impossible in 3e. Note that it's impossible for White Dragons to have magic, and Golden dragons always have it.
There's also a chance that dragons encountered will be asleep at the time, granting a free attack round (or the chance to flee as the case may be). This is a nice bit of archetypal flavour, and it always creates some tension when a sleeping dragon is discovered and the players argue over whether to take a crack at it. In some ways it makes the monster less dangerous, but it can also serve to lull the players into a false sense of security, thereby making it more dangerous. And you never know when the cagey beast is just foxing you...
The Dragons then get their habitats mentioned: Whites like cold, Blacks swamps and marshes, Greens forest, Blues the desert, Reds mountains, and Golden anywhere. Matches my vague Monstrous Manual recollections pretty well.
Golden Dragons are said to be the only Lawful dragons (the others not being known yet), and their ability to appear in human form is introduced as well. They won't serve any character, I guess for purposes of game balance - sure let the potentially treacherous evil dragons do it, but not the agreeable, possibly long-term companion good dragons!
Dragons also get a range of minor 1-point resistances, some of which make sense and some of which are arbitrary. I'm guessing this chart is one of the dragon rules that gets forgotten the most.
The rules for subduing Dragons then come up, and what it means is that you beat the dragon up until it surrenders and then you can order it around for a while. Or maybe even sell it, because there's a formula for how much money dragons are worth. You'd be forgiven for thinking that dragons are the only monster that can be subdued - this is the only place that the rule pops up. But the section on NPCs in Vol. 1 mentions subdual of monsters that implies it can be used on others.
A small amount of dragon ecology follows - if there are two dragons, they're always a mated pair. If there are more, then they are the kids of the happy couple. The parents will breathe automatically if their children are attacked, and if the female is attacked the male fights at double value. I guess that means you double the dragon's hit dice for the purpose of its attacks? Or do you double the damage? I lean toward the former. Anyway, it implies that adults of the same gender don't shack up together - though a 'mated pair' could be gay dragons, I guess.
Also: newsflash, dragons have a lot of treasure. The young ones have less, the old ones have more. Good luck getting your hands on any of it!
PURPLE WORM: Heh heh. Purple worm... It may just be my filthy mind, but I wonder if Gary was in a prurient mood when he created this monster. We'll never know, I guess, and that's probably for the best.
Anyway, get this - "These huge and hungry monsters lurk nearly everywhere just beneath the surface of the land." Dear god, that's terrifying! They reach about 50 feet in length and 10 in girth. They've got a poisonous stinger in their tail, but they probably don't need it, as they're able to swallow creatures up to ogre-size in a single bite (on a roll of natural 20, or one 4 over the score it needs to hit). This kills the victim in six turns, and in twelve it's been utterly digested and can't be raised from the dead ever. They never check morale, and they always attack.
So any time you think it would be awesome to live in Greyhawk for a while, remember that there are gigantic purple worms that can sting you to death or swallow you whole, digesting you beyond all hope of resurrection, attacking everything they meet - and that they are everywhere just below the surface!
Purple Worms are mentioned in Chainmail as a variety of dragon. They are called Purple Dragons or Mottled Dragons, but the description is the same. There are a few possible explanations here. One is that it's a cock-up by some sage who was trying to fill in the missing colours of the spectrum for chromatic dragons. Another is that purple worms are like some sort of dragon larvae, but given that they're more powerful than a lot of dragons it's not really feasible. Another idea I'm toying with is that dragons need to lie on big piles of treasure to live, or perhaps to retain their innate dragonosity. Perhaps Purple Worms are what becomes of dragons with no treasure hoard to sleep on?
SEA MONSTERS: Apparently these things are 'more for show than anything else'. Gary hasn't even bothered to stat them up, except to note that they're equal in size to a purple worm, possibly up to triple that size, and they inflict 3 or 4 dice of damage per hit. But they're just for show. Might put a few in an aquarium in the dungeon or something.
MINOTAURS: The classic bull-headed man of Greek mythology (complete with snide remarks from Gary about rules lawyers). They're big man-eaters, basically. (Does it even need to be said? It would be more efficient for Gary to note the monsters that aren't man-eaters.) Belligerent things, they always attack, never flee, and pursue as long as they can see their prey. The next humanoid up from the Ogre, basically.
CENTAURS: Mythological horse-men, though at no point is that noted in the text. They're at least semi-intelligent, and always wield weapons - clubs, lances, and bows, which is a touch more primitive than most semi-human species here. In melee they use weapons and their hooves. They're found in hidden glens, where they hide their females, young and treasure (and counter to regular D&D, they're listed in that order!). The wimmin-folk don't fight, though, nor do the young. There's nothing said about Centaur society, so I can play them as vicious war-like wine-guzzlers instead of the standard D&D hippie Centaurs.
UNICORNS: Unicorns can be ridden, but only by "maidens", and they mean that most literally. They can act as a lance on their first charge, and make saving throws as an 11th level Magic-User. In addition their eyesight is good, and they can Dimension Door once per day. So if there are people around that they don't want to meet, those people aren't going to see them. Unicorns are one of those cool mythological creatures that see little use in D&D, in my experience. I'd like to see a Paladin with one as a mount, though - but the maiden thing runs counter to how most of my players play female PCs.
Tomorrow: Fey! Demi-humans! Things with wings!