Ridley

Ridley is a high-ranking member of the Space Pirates and is one of the most common recurring characters in the Metroid series, so far appearing in every Metroid game except for Metroid II: Return of Samus and Metroid Prime 2: Echoes. Ridley commonly appears as a large dragon with powerful abilites. High Command usually chooses him to oversee major operations, such as the phazon mining on Tallon IV or the protection of the Zebes base. Although he is almost always defeated by his archnemesis, Samus Aran, Ridley is very strong, and has always come back to die another day despite the large explosions, extreme heat, and enormous kinetic energy to his spine that usually follow his battles with his hated foe.

History
Ridley rose to power in the Space Pirate hierarchy some time before the events of any of the games. However, when the Space Pirates began experimenting with Metroids, and, needing a place to observe them, Ridley raided Zebes, killing the Chozo and establishing Pirate rule on the world. He commandeered many battles on the planet against Galactic Federation forces, and defeated everything the Federation Police had to attack with. However, some time after these battles, he left Zebes on the Space Pirate Mothership for some other mission, only to later recieve a distress signal from Zebes and return to do battle with Samus Aran, a bounty hunter the Federation had sent to destroy Mother Brain. Ridley eventually confronted Samus. In Metroid, this battle took place in Norfair, whilst in Zero Mission, it took place in Ridley, an area named after him. In Metroid, Ridley is about Samus' height, if slightly taller, and merely hops around throwing fireballs at her. Samus can fire anything at him and he gets hurt. Once Samus defeats him, 75 missiles is added to her maximum amount. In Zero Mission, however, he is much more difficult. Only his chest can be damaged, and Ridley flies around and tries to kill Samus with his "classic" attacks - tail swipes, plasma breath, fireballs, scratches. After Samus defeats him, she gains an Unknown Item.

Ridley, after getting hurt enough, exploded and died nevertheless. To add to the irony, Samus blew up the Space Pirate base and incinerated whatever was left of him. However, Space Pirates, loyal to their leader, recovered parts of his body and infused them with machinery to recreate Ridley, now calling him Meta Ridley. Ridley then began overseeing the phazon mining and experimentation operations on Tallon IV, taking up residence aboard the Orpheon, a Science Team-controlled frigate that was experimenting with Parasites and their reactions to phazon. Samus, in pursuit of the Pirates, however, landed on the space station and caused a chain reaction which blew up the Reactor Core and initiated a countdown. En route out of the facility, she spots Ridley escaping his personal quarters and flying off towards the Space Pirate base on Tallon IV. She is in quick pursuit, although she eventually loses him and has to do ground-based recon.

On Tallov IV, Ridley apparently visits many of the Space Pirate bases, first going to the Phendrana Drifts to see the Pirate base, and then flying off towards the Phazon Mines, where he presumably remains until Samus engages him in battle once more.

In this battle, Ridley is equip with various powerful weapons: Mason Bomb Launchers, Multi-Missiles, and faster wings. His only weak spot is his chest, and Samus must fire things toward his chest to damage him. He makes long bombing runs across the sky to defeat Samus. Once Samus gets him down to one quarter of his health, Ridley's wings burn up and he is forced to stay on the ground and ram Samus consecutively. His chest is still weak, though, and Samus can still damage him there by stunning by shooting his mouth when he opens it to fire his Plasma Projector. As he is further damaged, his rams become faster and more brutal. Once his health is depleted, Ridley explodes on the inside, and Chozo statues blast his chest with powerful lasers. He falls off the Artifact Temple and into the Impact Crater, causing a huge explosion.

It is here Ridley's history gets scratchy; as this is when the events of Metroid Prime 3: Corruption take place. What is known is that he is rebuilt by his comrades and once again takes on a cyborg body. In the playable demo of Corruption, he fights Samus, and looks similar to his Prime appearance, only with phazon-blue undertones.

Even after these devestating battles, though, Ridley manages to rise again from the dead, this time with a purely organic body (possibly due to the fact his previous defeats as a cyborg left him wary of robotic abilites. This time, he destroys the Ceres Space Colony and steals the last Metroid from it. He and Samus have yet another skirmish, and Ridley, this time, escapes before she can prevail. He flies off to the rebuilt Space Pirate base on Zebes, where they plan to clone Metroids and make an army of them for galactic domination.

Ridley is once again is equip with his "classic attacks" (as a matter of fact, Super Metroid was the first to feature these attacks) when Samus finds him in his lair of the deep, central part of Norfair. Samus must defeat him again as one of the bosses to unlock access to Tourian. Like in Zero Mission and Prime, his only weak spot is his chest. After Samus defeats Mother Brain, Zebes explodes, but apparently, the explosion is not powerful enough to destroy all of the great dragon.

Ridley's remains are then frozen, possibly by the Galactic Federation, and transported to a Biological Space Laboratories station in orbit above SR-388. There, he is possessed by the X and taken to the deepest regions of Sector 1. There, he is once again killed by Samus, who happens to encounter him en route to the Operations Deck.

In Fusion, Ridley is quite difficult, due to the X that has fused to his system and presumably killed the actual Ridley. Ridley is very quick in the game, and Samus must constantly dodge for his contast tail swipes. Ridley can also grab Samus in this game and pull her up to his face. However, this is an advantage for Samus, who can merely damage him while being and when pulled up. Ridley will eventually turn red and then brown until he rots away, leaving behind a Core-X. Defeating this Core-X allows Samus to obtain the Screw Attack.

Although Ridley has seemingly been finally defeated, as all of his organic remains have been devoured by the X, he may once again miraculously return to wreak havoc on the galaxy once more.

Cameo appearances
In Super Smash Bros., Ridley can sometimes be seen flying on the background in the Planet Zebes stage.

In Super Smash Bros. Melee, Ridley appears briefly fighting Samus in the opening cut scene. Ridley is here holding a Metroid larva in his claws, which would determine that it was in fact the beginning of Super Metroid. The game also has a Ridley trophy.