Along with Kyogre and Groudon, Rayquaza is a part of the weather trio, serving as its trio master. In Omega Ruby and Alpha Sapphire, it plays an important role during the Delta Episode and is required to be caught there to fight Deoxys.
Rayquaza is a large, green, serpentine creature. It has red-tipped, rudder-like wings on its shoulders and down its body, and similarly patterned fins on the tip of its tail. Yellow ring-like symbols run across the length of Rayquaza's body and it has an additional yellow ring on top of its head. Rayquaza has two limbs with three-clawed hands, and two long, flat, horn-like structures on its head, with two shorter horns along its jawline. It has small, yellow eyes with black pupils, prominent pink gums, and two discernible fangs in its upper jaw.
As Mega Rayquaza, its body becomes longer and gains more features. Its head becomes longer with the Δ symbol appearing on its forehead. Its eyes now contain yellow pupils and red irises, and black, tree-like markings trail behind its eyes. Its red lips and teeth become gold, and the gold lines connect to those on its lower horns, which take on a broad, triangular shape. At the outer edges of its lower horns are long, golden, glowing tendrils that each extend to a green, fin-like structure; these tendrils have ring patterns that strongly resemble the yellow markings running along the length of Rayquaza's normal form. Its two upper horns become longer with a gold line running over them in a V shape, and each upper horn has another glowing tendril that ends in a circular shape with a spike. Along the length of its body are golden, glowing orbs placed where its ring patterns used to be. The chin, part of the neck, and parts of its serpentine body are changed to the color black. The fins running along its body are now marked with gold lines; the fins on its tail become entirely yellow and substantially longer. Particles stream from the long tendrils that extend from its jutting jaw; these particles can control the density and humidity of the air, allowing Mega Rayquaza to manipulate the weather. Its green hide sparkles with an emerald-like quality.
Inside Rayquaza's body lies an organ that contains the same power as a Mega Stone. A Devon Corporation scientist named this organ the mikado organ (Japanese: ミカド器官). By consuming meteoroids as it flies through the stratosphere, the mikado organ will be filled with enough energy to enable Rayquaza's Mega Evolution.
It is able to soothe the other members of the weather trio, even in their Primal Forms. Rayquaza is said to have lived for hundreds of millions of years in the ozone layer, where it feeds on water and other particles. Rayquaza is rarely seen by people; even in flight, its appearance is indistinguishable from that of a meteor. Rayquaza preys on the Minior in the Alolaregion. Rayquaza is the only known Pokémon capable of learning the move Dragon Ascent.
In Malice In Wonderland!, a Rayquaza appeared under ownership of Cynthia, but only as an illusion created by Mismagius. When Mismagius fuses with Rayquaza, it becomes the same color as the Mismagius, making it look like a Shiny Rayquaza.
To stop the battle between Kyogre and Groudon, Wally and Norman trained at the Sky Pillar and woke up Rayquaza. Five years earlier, Ruby's victory over a Salamence was the reason Norman was banned from the Gym Leader test as the wounded Salamence rampaged in a lab, accidentally letting Rayquaza, who was in captivity at that time, free. Having been ordered to recapture Rayquaza in the five years he was prohibited from attaining a Gym Leader position, Norman attended the Mossdeep Space Center and scrutinized its tracks, finally discovering that it slumbered atop the Sky Pillar when it wasn't scouring beyond Earth's atmosphere. With Wally's help, he was able to awaken and take command of Rayquaza, using it to calm Groudon and Kyogre in conjunction with Ruby's Red and Blue Orbs. When Norman fell under the strain of controlling Rayquaza without a proper medium, it escaped once again. It first appeared in Rayquaza Redemption I.
Rayquaza appears in The Subspace Emissary mode as a boss. After Diddy Kong lands in The Lake, Rayquaza lunges out of the water and grabs him, angry at being disrupted. Before it can further attack, Fox ejects out of his ship, which had crashed and been destroyed by Rayquaza earlier, and rescues Diddy Kong. Enraged, Rayquaza attacks Fox with Dragon Pulse, but Fox reflects its attack back at it, sending it reeling back into the water. Rayquaza soon launches back out and engages in battle against Fox and Diddy Kong.
A Sky High Pokémon. It normally resides high up in the ozone layer where it flies endlessly, so it is rarely seen. However, when Groudon and Kyogre began to fight, it appeared to calm them down. It has the ability Air Lock, which blocks all weather-condition effects. It has exceedingly strong abilities, and its attack power is especially remarkable.
Rayquaza appears as an occasional stage hazard in the Dragonmark Chamber of the Kalos Pokémon League stage. Appearing rarely, it flies across the stage at various angles, dealing damage to fighters. Its path is shown briefly by lightning before it appears, giving players time to avoid it.
This Dragon- and Flying-type Pokemon usually dwells high in the ozone layer, so it can't be seen from the ground. In the Kalos Pokemon League stage, it occasionally flies at great speed through the Elite Four's Dragon-type chamber, where any fighters in its path will be damaged and launched with great force.
Pokémon Pinball: Ruby & Sapphire: Rayquaza is the focus of the third and final Bonus Field. It can only be challenged after capturing Groudon or Kyogre and will then join the circuit of bonus fields. Rayquaza will bounce along from left to right, allowing the ball to roll under it if it is up. It will sometimes use Thunder to paralyze the ball if it is not moving fast enough, though it does stay still while it is unleashing the attack. Rayquaza will also sometimes use ExtremeSpeed to create two tornadoes that cause the ball to fly up into the air for several seconds if contact is made. Rayquaza must be hit 15 times in three minutes to win. After beating the round twice, Rayquaza will be captured.
Pokémon Mystery Dungeon: Rayquaza acts as the final boss, living on the Sky Tower. After it is defeated, Rayquaza helps save the world from a meteor. After the credits roll, the player can re-battle Rayquaza to recruit it.
Pokémon Ranger: Rayquaza can be captured in a bonus mission after the credits.
Pokémon Super Mystery Dungeon: Rayquaza first appears early into the game, fleeing to space in fear of Dark Matter's influence. When Dark Matter attempts to take the Tree of Life to space, Rayquaza and Deoxys use their energy to try and slow its ascent from above, with Rayquaza even Mega Evolving. Ultimately, when Dark Matter regenerates itself for the first time, it unleashes even more energy, turning both Rayquaza and Deoxys to stone. At the conclusion of the event, Rayquaza turns back to normal and takes residence at Dragon Gate and guards the Wind Looplet.
This Pokémon was unavailable prior to Generation III.
Rayquaza's design is probably based on the Chinese dragon and the lindworm. Its role is similar to that of Ziz in Hebrew legends. Rayquaza matches the description of the Aztec god Quetzalcoatl, who was depicted as a flying serpent, and created the boundary between the earth (including the oceans) and the sky. Its trait of being capable of inhabiting the skies, and living there while subsisting on nothing but dew and particles for centuries, also bears aspects of the legendary Chinese xian hermit sages and East Asian dragons.
Rayquaza most likely refers to Raqiya, the Hebrew word for "firmament". It also may be a combination of ray and quasar. Alternatively, it may be a combination of 烈 retsu (violent or furious), 空 kū (sky), and 座 za (seat or location), which can be taken to mean "one that sits in the ferocious heavens".
Rayquaza's mikado organ refers to 帝 mikado (emperor), another name for the Emperor of Japan or 天皇 tennō in Japanese, which can be translated as either "heavenly sovereign" or "king of the heaven/sky".
In other languages
Possibly from ray and quasar. Alternatively, it may be a combination of 烈 retsu (violent or furious), 空 kū (sky), and 座 za (seat or location), which can be taken to mean "one that sits in the ferocious heavens".