Ridley

Ridley (リドリー, Ridorii), also known as Geoform 187, is a high-ranking space pirate with cold, lifeless eyes, and appears to have been the general or commander of the Space Pirates stationed on Zebes, as well has being the supreme commander of the Space Pirate Confederation. He is highly intelligent and seems to have a great amount of hatred for the Chozo armor-clad bounty hunter, Samus Aran, and has faced her on numerous occasions. Somehow, he continues to survive despite multiple "deaths", possibly eluding to cloning technology. He is very defiant and persistent, and has always come back to fight again, despite the many large explosions, extreme heat, and enormous amount of kinetic energy his spine has suffered.

Biography
While his species' true name is not currently known, he is often regarded as a 'space dragon'. He is one of the last of his kind remaining after the Galactic Federation performed a series of mass genocide programs that brought his entire species to the brink of extinction.

Little no nothing is known about his pre-military background (if any in fact actually existed at all), but it is safe to say that he made his way through the ranks of the confederacy, gaining considerable favor amongst High-Command. However, Ridley's life became intertwined with Samus' very early on, when he was sent by High-Command to conduct a massive raid upon the Terran-established colonial planet K-2L; it was here that his orders were to restock fuel supplies and plunder. Due to his bloodthirsty personality and enjoyment for destruction, he let loose his pirates to cut loose and destroy whatever they liked. It was during this raid that Ridley came across a 3-year-old Samus, who attempted to befriend him; however, being the sadistic monster he was, he tried to kill her instead. The little girl was only saved when her mother, Virginia Aran, pushed her out of the way at the cost of her own life. At the same time, Samus' father destroyed the supplies the pirates were after but was killed in the blast, while Ridley himself was personally injured.

Eventually, Ridley became commander or general of the planet Zebes at behest of High-Command, which coincidentally was also where Samus had been trained by the Chozo years earlier. Here, he was ordered to establish a central command center beneath the planet's surface, where it was safe from the acidic rainstorms. His forces annihilated the native Chozo colony that had been already established, possibly to ensure the safety of his new base. Before this point, Zebes was considered by the Federation as a low priority, class XIII Wanderer Planet. However, when the Space Pirates stole the dangerous Metroid and rumors surfaced of them planning to clone an army of the organisms on Zebes, the Federation was quick to send its fleets into battle to remove the threat that had arisen. Ridley personally led his forces in many battles with the GF's fleets over control of the planet, and succeeded in defeating the Federation Police had to attack them with. With Zebes safe from Federation intrusion, he left the world in his flagship and Space Pirate mothership, the Avenger, to conduct other, more personal matters. It was only later that he received a distress signal from Zebes and had to return to defend it - it was here that he once again met with a now-grown Samus Aran, who had become a bounty hunter and who had been sent to the planet in an attempt to destroy the Mother Brain.

While the great Space Dragon threw everything he had at his old-yet-new nemesis, he did not come out the victor, and instead found himself nearly destroyed. Having sustained severe injuries at the hands (or, more specifically, cannon) of Samus, his loyal subjects recovered his fatally-crippled body and infused it with machinery, reconstructing Geoform 187 into "Meta Ridley". Seeking revenge, Meta Ridley led Samus from the Space Pirate-controlled Orpheus Space Station to Tallon IV. While here, he led her on a wild goose chase while he visited the many Space Pirate bases located thereon: first he went to the Phendrana Drifts, then moved on to the Phazon Mines, where it can be assumed that he remained until Samus' arrival. Later, he finally chose to engage her one-on-one at the Artifact Temple. With the battle's conclusion, however, Ridley found himself defeated again as the Chozo statues aided their savior by blasting him with powerful energy beams, sending him hurtling into the Phazon-infested Impact Crater.

Again, he survived, and later met Samus again on Norion. Again, he was defeated.

After his defeat in Norion, Ridley went back to the Space Pirate Home Planet, where he bacame the guardian of the last Leviathan and got heavily corrupted by Phazon, turning into Omega Ridley. However he was defeated when Samus Aran and the Federation corps invaded the planet, it's unknown if he died or survived the assaul,t as Samus' "Other Mission" (Where he makes an appearance) still doesn't have a place in the Metroid timeline.

Resuscitation
Despite the devastation that these battles wrought upon his body, he again managed to survive. This time he returned once more in a purely organic body (perhaps due to the fact that his previous defeats as a cyborg left him wary of robotic abilities). This time, he destroyed the Ceres Space Colony to steal the last remaining Metroid, which Samus had only just left there with the scientists to study its energy producing capabilities. Samus had received a distress call once more, and Ridley came face to face with her yet again, but this time he fled before she could prevail (unfortunately for him, if he had remained just long enough, he would have been able to rid himself of her once and for all, due to her weakened form), setting the colony's self destruct timer as he left. Now off the long-lost colony, he flew off to rebuild the Space Pirate base on Zebes, where they planned to continue their hopes to clone the Metroid species to make an unstoppable yet controllable army for their attempts at galactic domination.

Ridley chooses to remain deep in his lair beneath Norfair, and this time awaits for Samus to come to him. At some point before this time, it seems that the original Metroid escaped his grasp, as the vial he had carried off with him that it was in lay shattered upon the floor of his lair. Samus and him fought yet another great battle, but again, he was defeated. Somehow he succeeded in escaping the planet despite his injuries before it was destroyed upon the death of Mother Brain.

Ridley X: The End of Ridley?
Like some recurring nightmare, Samus found the frozen remains of Ridley located within a frozen stasis chamber upon the Biologic Space Laboratories research station's main deck. To her relief, he was frozen successfully and could not move or provide any kind of terror in this state. Unfortunately, his inability to move led to his eventual infection by an X Parasite. This X cracked the frozen Ridley and destroyed his corporeal form once more, apparently finally finishing him off. Samus soon encountered this X-clone of him and destroyed it, as well, leaving no known trace of Ridley as the BSL crash landed into SR388.

Due to the other Space Pirates found on the BSL, it seems likely that they invaded the laboratories, only to be subdued without Samus' intervention.

Trivia

 * Ridley is named after Ridley Scott, the director of the first Alien film from the Alien film series, from which the Metroid games took a lot of inspiration.
 * Ridley is one of only two characters in the Metroid series to best Samus in a fight. This occurred during the Super Metroid introduction stage, where he is able to incapacitate her enough to steal the last Metroid and accomplish his mission.  The other is Dark Samus.
 * Ridley is the most common reappearing master or boss in the Metroid series, and has such appeared in every Metroid game to date except for Metroid II: Return of Samus, Metroid Prime 2: Echoes, and Metroid Prime Hunters.