The Legendary Birds
Here we are, the first Legendary Pokemon ever introduced in the entire franchise---the Legendary Birds. Before we talk about them, let's talk about Legendary Pokemon. To put it simply, Legendary Pokemon were originally introduced as the "secret bosses" of the Pokemon series, hidden away deep within the game's toughest dungeons and completely optional during the main adventure, but necessary if the player wanted to complete their PokeDex. Legendary Pokemon are overall statistically the strongest Pokemon in the game, although there are non-Legendary Pokemon who exceed them, and also extremely rare---each game generally has only a single individual of a Legendary species available, and once you caught or defeated that Legendary Pokemon they were gone for good, although later games began to have them respawn. Personally, the Legendary Pokemon are hard enough to catch as is, and I think totally keeping the player from obtaining them if they screwed up wasn't the best design decision, so I'm perfectly okay with them easing up on that trait. Legendary Pokemon also are unable to breed, do not have genders, and do not evolve, although as we'll see all those traits have technically been broken by special exceptions introduced in future Generations, but most of them still follow those rules.
Legendary Pokemon are an important part of the Pokemon franchise, but also an element that in recent years has come under criticism by long-term fans. The issue? Well, to put it simply, most people see Legendary Pokemon as simply PokeDex filler---in the competitive scene they have their use, of course, but most players who play Pokemon like to use Pokemon they've raised throughout the adventure, and generally adding a Legendary to your team is seen as very cheap and going against the main appeal of the series, raising a weak Pokemon into a strong one through hard work. And while Legendary Pokemon were once simply an additional part of the Pokemon experience, in recent years they've been pushed more and more to the forefront, becoming vitally important to the game's plot, and the amount of them introduced each Generation has skyrocketed, with XY being the first game to actually dial back on them---although it also introduced Mega Legendary Pokemon into the mix. It seems most people would rather have more "normal" Pokemon over Legendary Pokemon, and the excess amount of Legendary Pokemon has greatly weakened their appeal. By this point, basically everything you can imagine has been covered by a Legendary---we basically even got God---and I think fans are just sick of them. To be fair, I actually do like the designs and themes of a lot of Legendaries, however I myself never actually use them, and don't really care about catching them anymore either. They make cool Pokemon to make movies about though, but I really think Game Freak needs to go back to the Generation I roots where Legendary Pokemon were powerful and rare, but an optional part of the game and didn't have such extreme powers and such.
The Legendary Birds introduced a reoccurring archetype known as the "Legendary Trio", a group of three similar Legendary Pokemon who share similar stats, designs, and sometimes Types., in this case all being part-Flying. In a couple situations, there's also a fourth, more important member introduced known as the "Trio Master", who the Birds have in some canons, but not in the main games. They're typically available earlier than the other Legendary Pokemon, such as the Legendary Birds in Generation all being catchable before the Elite Four if you wished to use them, and are also statistically weaker, having 580 BST and thus being eligible still for most in-game Battle Facilities that the stronger Legendaries are banned from. They usually don't play much of a role in the main story of the game, and finding them is completely optional, but can be fairly challenging since you'll need to search for them instead of them coming to you like the Mascot Legendaries. Since Generation III, the main Legendary Pokemon of each Generation decorating the boxes have also been comprised of Legendary Trios, however these Legendary Trios are more powerful, and typically are called a "Mascot Trio" to differentiate them. Legendary Trios are my favorite part of the Legendary cycle, and the one type of Legendary I wouldn't mind staying, and was actually very disappointed XY lacked a new Legendary Trio, merely using the Legendary Birds once more without any real reason behind their appearance, and limiting every player to only 1 via a tedious chase quest. Maybe "Z" will deliver on that though...
Articuno, Zapdos, and Moltres are interesting among Legendary Pokemon because they really don't have any story behind them at all in the actual games, they're just three rare, powerful birds representing the popular RPG elemental-trio of Ice, Lightning, and Fire, and probably due to this reason they're easy to throw into later games without much explanation behind their appearance---they've made 12 main game appearances I believe. It's generally thought that there's only one of each in existence, although the various canons seems to imply that they are capable of breeding and such, and there might be a couple of each species flying around the different Regions. In the show, though, the Legendary Trio were given a starring role in the second Pokemon Movie as "guardians of nature", and capturing them could lead to the complete destruction of the ecosystem as we know it, but nothing in the games support that, nor do the games ever link the Legendary Birds to Lugia, who in said movie was said to be their "Trio Master". Honestly, the games don't even really suggest that the Legendary Birds even are familiar with one another or linked beyond all three being birds, it's probably more of a man-made title. I don't need Legendary Pokemon to have a ton of back story, but I wish they could give these guys some sort of legend in the games to make them a bit more interesting. I've honestly never really been a fan of them, and while I like their simplicity, I find almost every other Legendary cooler than these guys.
In the dub, they have a very cute naming scheme of "uno, dos, tres", whereas in Japan they're just named Freezer, Thunder, and Fire. Hey, it probably sounds cooler to non-native English speakers. Also Westerners will see them as representing the original trilogy of Generation I games, whereas like with the Generation I Eeveelutions it's merely a coincidence and leaves out "Green".
#144 - Articuno
Ice/Flying
Articuno is the first of the Legendary Birds, but there's no indication that there's any hierarchy among them outside of their English names, so don't think of him as the leader. Articuno was one of the few Ice-types introduced in Generation I, and the only apart from Jynx who wasn't part-Water---I also feel it's easily the most "icy" of the original Ice Pokemon, although you could probably mistake it for a Water-type Pokemon given that it appeared at Seafoam Islands, and might be thinking the Legendary Birds had the same Type as the Eeveelutions and thus it was like Vaporeon. It was probably the most annoying Legendary Bird to capture due to the Seafoam Islands being a complete mess to navigate and very frustrating, and I remember saving it till the end of the journey because I didn't want to bother with it at first. Articuno is the slowest and most defensive of the Legendary Birds, which doesn't really pay off due to being an Ice-type Pokemon and having a ton of weaknesses---back in Generation I, all the Legendary Birds were good, with Articuno in particular being the only one who could stand up all the Rock/Ground Pokemon, but throughout the years they've all sort of gone down in usage, and Articuno appears to have suffered the most due to just not being able to keep up with everyone else in speed and Ice never getting any better. Nowadays, I believe he's considered the weakest of the Trio, but on the other hand it seems that he's the most popular of the Legendary Birds aesthetically, or so I get that impression.
The Legendary Birds have rudimentary elemental powers, with Articuno of course being able to control ice---it's said that when it flies, snow is said to fall. The PokeDex states that it's "semi-translucent wings" are made of ice, but none of its appearances have ever really represented this, they just look like regular, blue feathers and have never been shown to be transparent, even in the 3D games where that'd be easier to model. I sort of wish they used its Shiny coloration as its default, as it fits more in my opinion. Its original sprites had it look almost like a swan, but since then it's toughened up in terms of appearance, and now reminds me of some sort of powerful bird of prey, like an eagle, and makes him feel like he probably has a bit more authority than the other two. None of the Legendary Birds seem to be based off any specific species of bird, but Articuno is said to look like a "white-throated magpie-jay", which I sort of see but there's no direct evidence beyond simply similarity in appearance.
The other Legendary Birds appear to be based off real-world mythological birds, but I don't recall ever hearing about one with control over ice and snow, so Articuno seems to be the exception to this. Or maybe there is one and it's just obscure and I've never heard of it? Beyond simply controlling ice, there's only one other legend associated with Articuno which says that those lost on snowy mountains will see this Legendary Bird---but the PokeDex is vague about what this means. Does Articuno rescue them from their fate by leading them to safety, or rather does it appear to them as their die, possibly being the reason they got lost in the snowstorm in the first place? I'd like to think its the former, but Pokemon can be pretty brutal so it wouldn't surprise me if it's also the latter.
All the Legendary Birds appeared in Movie 2, but mainly just got captured and sat around in bird cages for most of the movie. Individually, they've all had a few appearances, Articuno got an entire mini-arc in Johto dedicated to it which also saw the return of Todd Snap---for some reason. In the Battle Frontier season, an Articuno actually befriended the Factory Head Nolan and was used by him in a battle against Ash's Charizard. I get that Frontier Brains were the first in-game trainers to use Legendary Pokemon iirc and the anime wanted to show that, but this pissed me off---the Battle Factory was all about rental Pokemon, and I remember getting hyped wanting to see Ash using a team of rental Pokemon for once to mix things up, but the show just drops that completely in favor of Articuno vs. Charizard. Total missed opportunity, and I remember the episode being pretty lame. Articuno also was believed to have appeared in the very first episode of Pokemon, but of course it turned out to be an entirely different Legendary who'd be introduced officially in Generation II...
#145 - Zapdos
Electric/Flying
Zapdos is the second Legendary Bird, and arguably the most popular one overall due to his looks and power---I imagine part of his popularity stems from the fact he was by-far the easiest Legendary Bird to find and capture due to only needing Surf to reach him and hiding in the Kanto Power Plant, a far easier and simpler dungeon to nagivate than Seafoam Islands and Victory Road. As a kid, he was the first Legendary Bird I caught, and I recall actually using him through a bit of the late-game since I was a pretty poor player and needed to rely on his power to get me through. Zapdos has always been the most powerful of the Legendary Birds in the competitive scene, possessing the best Speed and tied for the highest Special Attack, especially in the early days where his only big weakness was his inability to handle the Rock/Ground Pokemon of Generation I, and he's still the most powerful, although like all the Legendary Birds he's suffered some stiff competition such as another Electric/Flying Legendary Pokemon appearing on the scene in Generation V, and of course Stealth Rock, although atleast he only takes 2X damage from that unlike Articuno and Moltres. But if you want a cool-looking Legendary, Zapdos is your bird.
With that being said, Zapdos is one of those designs I look at now that I'm older I feel a bit embarrassed that I found it cool as a child. Don't get me wrong, it's by no means a bad design, nor is it as try-hard as some later Legendaries, but it does look quite awkward especially in the face area with that Woody Woodpecker nose, and visually it noticeably stands out compared to the other Legendary Birds who have slightly more elegant designs whereas Zapdos is quite sharp and edgy. Like with Articuno, Zapdos doesn't appear to be based on any specific real-life bird, rather its design is all about giving the impression of "electricity", which I think it does a good job with more so than Articuno's attempts to look "icy", but there's really no subtlety here like most Electric-type Pokemon. He's also probably the only Legendary Bird whose original sprite actually matched the art somewhat, whereas Articuno and Moltres looked quite different.
Zapdos of course has control over the power of storms, and is said to cause thunderclouds to appear whenever it flaps its wings as well as dropping down lightning bolts---but does it truly control the power of storms, or does it merely appear when they roll in? One entry says it lives within the thunderclouds, and is given power when hit by lightning bolts suggesting that it depends on the storms rather than the other way around. It fittingly had Lightning Rod as a Hidden Ability in Generation V, but was unaccessible through any legit means and by Generation VI, it was given Static instead, although you still can't get Legendary Birds with their Hidden Abilities, so they're all stuck with Pressure, the default Ability for older Legendaries it seems. Zapdos is likely based off the North American indigenous people mythological creature known as the "Thunderbird", which shares the same abilities as Zapdos to cause storms and such by merely flapping its enormous wings. The actual Thunderbird is believed to have been based off sightings of possibly bald eagles, due to their impressive size and wingspan, and actual imagery of the Thunderbird doesn't look anything like Zapdos as it didn't literally look like a bird made of lightning nor did it have the giant beak. But I imagine Game Freak based the general idea of Zapdos on the lore associated with the creature, and weren't going for accuracy anyway. By the way, the Thunderbird who appears in Zelda II is likely not related to the mythological one whatsoever---that name is a dub invention, and originally it was called Boruba, and official artwork of it makes it look like it was meant to be based off some sort of Harpy rather than a Thunderbird.
Zapdos appeared in Movie 2, but later got a filler episode dedicated to it at the far end of Johto, the last Legendary Bird to officially appear in the show, where it was shown to roost at a special lake containing a magical crystal said to restore the energy of Electric-type Pokemon. Yeah, it was a Johto episode. It also made a few quick cameo appearances during the Diamond and Pearl series, likely as a shout-out to the Legendary Birds roaming Sinnoh during the post-game of Platinum. But overall, for arguably the most popular Legendary Bird, it's had the least amount of spotlight in the show.
#146 - Moltres
Fire/Flying
The last Legendary Bird, Moltres in the original Red and Blue appeared deep within Victory Road if the player was willing to explore it further, although like all caves throughout the Pokemon experience it could be quite a pain, but in the Gen III remakes, it was relocated to the new Sevii Islands. Although most of the islands could not be explored till after beating the Elite Four, the first three could be explored as soon as one defeated Blaine and Moltres happened to make its home on the first one, Knot Island. I'm not sure why they decided to move Moltres, but I guess they wanted to give it its own dungeon that fit its Type rather than sticking it in Victory Road? Moltres has the highest Attack and Special Attack of the Legendary Birds (although it shares the Special Attack with Zapdos), but it's hurt due to its Type which is destroyed by Stealth Rock, and generally it seems to be the weakest of the Legendary Birds in the competitive scene. It got a bit more use once it gained Hurricane in Generation V, but it seems there's more worthy Legendary Pokemon to use over it. I also feel it's the least popular of the Legendary Birds in general---I imagine popping up in Victory Road very few people used one in-game, saving it for the post-game, and also I don't think people really like its design.
A good criticism of Moltres' design I've heard is that there's no "stability" to it. With certain Pokemon, they have a look, and that looks stays with them, but Moltres' design changes constantly depending on the artist and medium---are its wings and tail totally made from fire? Or are its wings just yellow with flames coming out the ends? Sometimes Moltres looks really cool but other times I've seen it described as looking like a "rubber chicken" someone lit on fire. The fire part of it is pretty cool, but I agree that its actual body does kind of look like some kind of weird chicken, and very rarely do I feel it's properly represented in a cool way, most of the time it does seem to have somewhat of a goofy look to it. But for what it's worth, it achieves what it sets out to do---resemble a bird who controls fire---so I can't hate on it too much if it accomplishes what its motif intends to portray. Moltres controls fire, and is said to even bring spring to cold regions when it appears through its wings that rain down embers wherever it flies.
Some people think Moltres is based on the legendary Phoenix, due to the fact it can regenerate itself if damage by nesting in volcanoes, however besides the "rising from ashes" bit I don't think traditional phoenixes were ever associated specifically with fire, and Generation II introduced a much more loyal Phoenix-based Pokemon. It seems to be based more so on the Vermillion Bird of Chinese mythology which like Moltres is said to be perpetually covered in flames, as well as possibly the Slavic Firebird, who is also commonly said to be a mythical bird with flaming feathers. Or maybe Game Freak just wanted to make a bird that was on fire? I mean, that's basically what they did with every other Fire-type Pokemon, just took an animal and lit it on fire.
Moltres appeared in Movie 2, but was the only Legendary Bird to actually get focused on during the Kanto series in the show, where its flames are said to be used to light the torch of the Pokemon League as a nod towards the Olympic Torch, and that's not the only reference to the Olympics---the Santa-looking dude who pops up at every League, Mr. Goodshow, was based on the current President of the Olympic Committee, Juan Antonio Samaranch as his original name is a pun on his, "Tamaranze". However, as of the next Pokemon League in Johto, the flame was said to be from a new Generation II Legendari Fire-type bird rather than Moltres, and in subsequent Leagues I believe it has remained as the owner of the flame as opposed to Moltres. Moltres' appearance in Kanto can be debated, though, because in "All Fired Up" which featured the torch, the flames themselves somehow took the appearance of Moltres rather than the actual Pokemon being present, or something, in order to fight Team Rocket. So, yeah, it's dubious. I used to think Moltres actually flew by in "Lights, Camera, Quacktion" when Jigglypuff put everyone to sleep as you see a bird fly over everyones' head, but that was actually just a Fearow this whole time. Huh? Moltres later got a Pokemon Chronicles episode dedicated to it, the only episode of the show to ever feature the Sevii Islands as it takes place on Mt. Ember, but the dub actually messed this up---the most important part of this episode is that it probably, no kidding, straight up featured Ash's dad, but left it very ambiguous. Moltres recently got an episode in XY as well, somewhat of a re-tread of the Articuno plot in Johto with a photographer wanting to capture it on film, referencing its appearance in XY. Moltres appearing fits though with the games, as it only appeared if the players started with Froakie---who is Ash's Kalos Starter.