Ridley

Ridley is a high-ranking member of the Space Pirates and one of the main villains in the Metroid franchise. He first appears in the first Metroid game. Ridley is directly responsible for the murder of Samus Aran's mother and partially responsible for the death of her father. Ridley also has a recurring cybernetic form named Meta Ridley.

He is named after, director of the 1979 film Alien, which has been described by Yoshio Sakamoto as a "huge influence" on the world of the Metroid series.

Metroid
In Metroid, Ridley is one of the two minibosses, the other being Kraid. He is fought in a room within his own lair. His room consists of a large, floating platform with two levels of differing height (with the boss on the highest), and a pool of lava located below. In his debut, Ridley is approximately Samus' height, and despite having wings (albeit very small ones), Ridley cannot fly, and his attack is to instead hop up and down while spitting zigzagging fireballs at Samus. A common trick was used to effortlessly defeat Ridley by standing directly in front of the ledge on which he stands, which is underneath him and out of range of his attacks.

Samus can use any weapon of her Power Suit possesses to damage Ridley. Ridley's fireballs are indestructible and excel as a defense mechanism, destroying any long-range weapon and nullifying the blast from Bombs on contact. If Samus has the Ice Beam, she can temporarily freeze all of Ridley's projectiles, rendering him incapable of shooting out any others until the ice thaws. Depending on the position the fireballs are frozen in, they can either leave Ridley completely exposed to any attack, or prevent anything, including Samus, from getting close to him, thus careful precision is required when using the Ice Beam.

In the Family Computer Disk System version, Ridley's boss fight is considerably more difficult. Each fireball created by Ridley has a different trajectory randomly picked from a set, so Samus has to deal with projectiles traveling at different speeds with small or large zigzag patterns, leaving no safe zone. The Nintendo Entertainment System version can only choose a single trajectory for all of Ridley's fireballs due to its less powerful hardware. This means there are multiple safe zones in the room where the fireballs cannot reach, allowing Samus to effortlessly defeat Ridley by either standing next to Ridley and shooting him or by standing a set distance away to jump and fire at Ridley.

Super Metroid
In Super Metroid, during the intro, Ridley kidnaps the last remaining Metroid and has a brief skirmish with Samus, thereby setting off the whole plot of the game. Later in the game, he can be found in the deepest, central section of Norfair, where the player must fight him. Afterwards, the container in which the Metroid hatchling was housed is found shattered, with the hatchling nowhere to be found. It is not an empty victory, as Ridley's defeat unlocks the stronghold of Tourian, where both the hatchling and Mother Brain yet await Samus's arrival.

Several of Ridley's attacks were introduced in the game, such as grasping Samus and using his tail swipes.

Metroid Fusion
In Metroid Fusion, an X Parasite copies Ridley's DNA, as Ridley's frozen body falls apart in the sub-zero containment room of the Galactic Federation research lab. Near the end of the game, Samus fights "Ridley-X", larger and more powerful mimic version of Ridley. Ridley-X's attack pattern is nearly identical to that of Ridley's Super Metroid incarnation. Oddly throughout the battle Ridley appearance keeps changing from an emaciated, skeletal form into a violent muscular form.

Metroid Prime series
In Metroid Prime, after Ridley was defeated on Zebes in the first Metroid game, his remains were recovered and reconstructed with cybernetic implants, turning him into a cyborg. He is known as Meta Ridley for the entirety of Metroid Prime.

In Metroid Prime 3: Corruption, Meta Ridley makes a reappearance. Late into Samus's journey, Meta Ridley becomes Omega Ridley, following his infusion with Phazon.

Metroid: Zero Mission
In Metroid: Zero Mission, Ridley is part of the boss duo along with Kraid as in the first game, although he bears more similarity to his incarnation in Super Metroid. He is normally first seen in a cut scene in which he is commanding a Space Pirate mothership in much the same fashion as in the Metroid e-manga. As Samus dispatches Kraid and continues exploring Zebes, he has the mothership land on the planet's surface and sets out to put an end to Samus' progress personally. Although he is defeated, the mothership and the Space Pirate troops aboard it are the focus of the final segment of the game, which was not present in the original game.

A robot in Ridley's image, unofficially referred to as "Mecha-Ridley" or "Robo-Ridley", also appears as the chief guardian of the mothership and the final boss of the game. It relies primarily on a powerful claw attack, in addition to various projectiles such as fireballs, missiles, and beams shot from the eyes. Unlike the real Ridley, this robot form remains grounded throughout the entire battle although he does have what resembles a jet pack on his back that shoots missiles. If the player has collected 100% of the items in the game by this point, this robot's attack power and durability are increased by 50% and 200%, respectively.

The game appears to have retconned the fact that Ridley is a native inhabitant of Zebes, as it is stated that the Chozo were inhabitants of Zebes and that it was where Samus was raised after her home planet was raided by Ridley.

Metroid: Samus Returns
In Metroid: Samus Returns, while Ridley is absent from the original Metroid II: Return of Samus, he appears in the game as Proteus Ridley. Returning from his prior defeats in the Metroid Prime series with fewer cybernetic implants, Proteus Ridley ambushes Samus and attempts to capture the last living Metroid just as they are about to leave SR388.

Super Smash Bros.
In Super Smash Bros., Ridley can occasionally be seen flying in the background of the Planet Zebes stage.

Super Smash Bros. Melee
Ridley makes a cameo appearance in the opening cinematic of Super Smash Bros. Melee, where he can be seen battling Samus. There is also an obtainable trophy of Ridley.

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, Ridley is fought twice in Adventure Mode: The Subspace Emissary.

The first time he is encountered, he is fought by Samus and Pikachu. As the two reach the exit to The Research Facility, where her Power Suit had been held, Ridley appears without warning and snatches up Samus. Roaring, he slams her into a wall and drags her along it. Pikachu comes to Samus's rescue, hitting the space dragon with a Thunder attack, after which the battle begins. Ridley fights similarly to Master Hand, using many brutal physical attacks. When he is defeated, he falls off the arena.

He later reappears as Meta Ridley, attacking a group including Captain Falcon, Captain Olimar, R.O.B., Samus Aran, Pikachu, Diddy Kong, and Donkey Kong as they try to escape the floating Isle of the Ancients before it is engulfed in Subspace. As this battle is fought while trying to escape an island, there is a set time limit of two minutes that the player has to defeat Meta Ridley, who is more difficult to beat than Ridley was. Additionally, there is the added difficulty of the battle taking place on top of Captain Falcon's ship, the Falcon Flyer, so it is possible for the player to fall off the edge and lose.

Meta Ridley uses some of the same attacks as Ridley did, such as scraping his tail across the top of the Flyer and firing fireballs, but also shows additional ones that involve grabbing the Falcon Flyer and lowering it down with his weight, sometimes even lowering it off of the screen. Fortunately, most of Meta Ridley's attacks can be avoided by jumping off the Falcon Flyer at the right time. Meta Ridley's fireballs can also be reflected right back at him.

Both fights are reprised in The Great Maze with any characters that have been rescued throughout the Subspace Emissary. He is also fought in the Boss Battles game mode. There is no time limit when fighting Meta Ridley in either The Great Maze or in Boss Battles mode.

Super Smash Bros. for Wii U
In Super Smash Bros. for Wii U, Ridley is a stage hazard boss on the Pyrosphere stage. His physical appearance, like Samus's, is based on his appearance from Metroid: Other M. Once attacked enough by a player, Ridley allies with that player, and attacks the other players. He can also transform into Meta Ridley by absorbing enough energy. He can be defeated, and, as if he was a character, defeating him rewards the player with a K.O. point; he can be defeated by his own ally as well.

Super Smash Bros. Ultimate
In Super Smash Bros. Ultimate, Ridley is a playable character for the first time, announced during the E3 2018 Nintendo Direct alongside fellow newcomers Inkling and Daisy. His appearance in this game seems to primarily be based off of that in Super Metroid, while he has a similar size to his appearance in the original Metroid. His Final Smash involves him slamming an opponent or opponents against Samus's Gunship and shooting plasma at the ship; the falling gunship can be seen in the background after the attack. Two of his alternate costumes swap him out for Meta Ridley (although he is still referred to in-game as simply "Ridley").

Ridley does not share a victory theme with Samus, instead using an intense and sinister variation of the Metroid victory theme; the flourish itself is shared with Dark Samus, and this trait is shared with fellow newcomers Chrom, King K. Rool, and Piranha Plant, as well as several veterans, namely Meta Knight, Bowser, Bowser Jr. (and the Koopalings), Rosalina & Luma, Dark Pit, Robin, Lucina, and Corrin.

In his reveal trailer, "A Piercing Screech" Mario, Mega Man, and Samus Aran are traversing through a mechanical room on a walkway. Ridley stealthily takes Mega Man and Mario out by impaling the former with his tail and crushing the latter's head. Samus eventually senses something amiss and points her arm cannon behind her, only to find Mario's discarded hat. Suddenly, the walkway quakes with Ridley bursting out from underneath and knocking a shocked Samus off her feet. Ridley then proceeds to roar before giving an inhuman smirk as he twirls Mario's hat around his finger. In the ending of the trailer, Ridley, after presumably causing a blaze to kill Samus, is flapping his wings only to glare in slight irritation when Zero Suit Samus uses her Jet Boots to leap from the blaze and descend down to attack him.

Ridley is a heavy fighter, being heavier than Snake, R.O.B., and Banjo & Kazooie but lighter than Samus, Bowser Jr. (and the Koopalings), Dark Samus, and Terry, while having the same weight as Wario, Ike, Simon, and Richter.

Nintendo Land
In Nintendo Land, an animatronic Ridley appears as a recurring antagonist in the Metroid Blast attraction. Ice Ridley, a version of Ridley unique to this game, also appears.

Ridley first appears in the seventh level of the Assault Mission mode, Destroy 10 Cyclons. Unlike in its later appearances, the Ridley robot cannot be defeated directly, but it is possible to make it leave the arena by shooting all its weak spots multiple times. This gives no reward, however, and only makes the rest of the mission much easier as he will not disturb the player. Ridley later makes a proper appearance in the twentieth and final main level, "The Final Battle". Here, Ridley is fought in three stages, in each of which the Mii players must destroy targets on its chest, mouth, and tail. In the first stage, Ridley attacks by firing beams from its mouth and shooting its tail. The second stage adds a target on its right hand, which detaches from its main body and attempt to attack the Miis, as well as firing missiles at the Miis. The final stage of the battle places one additional target on its left hand, which fires beams as well.

In the extra stages of Metroid Blast, Ice Ridley is introduced, but the normal Ridley makes another two appearances as well. In level twenty-eight, "Ridley and Ice Ridley", the Miis must fight both forms of Ridley at the same time, as implied by the title. Ridley appears for the final time in level thirty, "The True Final Battle". As with its first appearance, Ridley cannot be defeated; it is merely a distraction for fighting the level's actual opponent, Kraid

Captain N: The Game Master
Ridley makes a cameo in the episode, "Gameboy" in Captain N: The Game Master, in which he is depicted as a large orange dragon. He also makes appearances in the Valiant adaptation of the series released for the Nintendo Comics System, where he looks more like his American artwork for Metroid, being a blue, multi-eyed, pteranodon-like alien.

Palutena's Guidance

 * Pit: RIDLEY CONFIRMED!
 * Palutena: Uh, yes. That's Ridley. Samus's archnemesis.
 * Pit: I never thought I'd have to fight an alien space dragon in Smash...
 * Viridi: Kirby's a space alien too, ya know! Jury's still out on him being a dragon, though.
 * Palutena: Ridley may look like a mindless killing machine, but he's exceedingly intelligent. He's also the leader of the ruthless Space Pirates.
 * Pit: So what's the story behind him and Samus?
 * Palutena: Ridley killed Samus's parents when she was young.
 * Pit: That's messed up!
 * Palutena: Samus and Ridley first fought in the depths of Norfair on Planet Zebes. They crossed paths again when Ridley stole the Baby Metroid. Meta Ridley was made through genetic engineering and cybernetic enchancements. Omega Ridley is the one infused with Phazon... Neo-Ridley was born when an X parasite absorbed Ridley's genes. And yet another Ridley was created by cloning cells found on Samus's suit!
 * Pit: You sure know a lot about Ridley. And none of it is about how to fight him!
 * Viridi: There's also a robot version of Ridley. He built it himself, which officially makes him a narcissist.
 * Pit: Is that canon?
 * Palutena: Canon or not, all of these Ridleys shared the same fate-they were all defeated by Samus.
 * Pit: Not surprising. Samus is a beast!
 * Palutena: So is Ridley. Mind the sharp barb on his tail.

amiibo

 * Ridley is the leader of the Space Pirates in the Metroid™ series and Samus’s long-standing rival in battle. He looks like a pterosaur but has high intelligence and a brutal nature. Ridley utilizes wings for a full range of flight and attacks with fireballs from his mouth and whips of his tail.

Super Smash Blog bio

 * Joining the battle from the storied Metroid series, Ridley's long tail and sharp claws let him unleash a torrent of devastating attacks. His Final Smash is a powerful stream of plasma breath intense enough to bring down Samus's starship.

Trivia

 * Ridley appears in Nintendo Monopoly, in which he takes the place of Tennessee Avenue. He costs $180.
 * Ridley's trophies in Melee and Brawl both state that he is the head of the Space Pirates on Zebes. This is false, however, with the real head being Mother Brain as well as Space Pirate Command.
 * Due to the time limit that is given during the Meta Ridley battle, Trophy Stands will appear more frequently, especially on the easier skill levels.
 * Ridley's stock icon for Super Smash Bros. for Wii U uses his appearance from Super Smash Bros. Brawl, instead of his Metroid: Other M appearance.
 * Ridley's stock artwork in Super Smash Bros. Ultimate resembles from Super Smash Bros. for Nintendo 3DS / Wii U.
 * Ridley's splash screen introduction in his Super Smash Bros. Ultimate reveal trailer; "Ridley Hits the Big Time!", may be a reference to "Ridley is Too Big", an Internet meme originating from arguments against Ridley being a playable character in the Super Smash Bros. series.
 * His appearance in Ultimate is the first game to directly showcase his more intelligent and cunning personality traits, as while various sources in both prior Smash games as well as his home franchise (most directly in the Metroid manga) strongly implied that he possessed these traits, they were not immediately apparent in his characterization in the games, where he is generally portrayed as simply a monster.