Technically, Ash never caught any legendary pokemon but he came close to several legendaries who were emotionally attached to him. Some of them being Suicune, Azel, Solgaleo, Tapu Kuku and Reshiram. Also our boy has caught pokemons of other categories like Mythical and Ultra beast, i.e, Melmetal and Naganadel.
Ash has had multiple chances to catch a legendary Pokémon throughout the series but never did, despite forming close bonds with a few of them in the wild.
Eventually, Ash helps the legendary Pokémon when they are pursued by members of Team Rocket. However, he doesn't catch them because of their role as guardians.
In the Sinnoh League, Sceptile made its legendary return and went up against Tobias' Powerful Darkrai, which had previously defeated many of Ash's best Pokemon. Sceptile eventually won against Darkrai, however, Solidifying its status as one of Ash's strongest Pokemon.
The one exception to this is Meltan, which despite being a Mythical was but one of many. Many would say that Meltan's evolution Melmetal is the absolute rarest Pokémon he's captured and battled with, as it's still a Mythical Pokémon, and that's a fair point.
Ash Ketchum finally claims Pokémon Master after two decades trying to catch 'em all. In the 139th episode of "Pokémon the Series: Sun and Moon," Ash Ketchum finally "caught 'em all" and became a Pokémon Master.
Ho-Oh is the first Legendary Pokémon Ash encounters and the first Legendary to appear in the anime series.
1. Arceus. Arceus is, without a doubt, the most powerful Legendary Pokémon. This Normal type Mythical Pokémon is the creator of the universe and thus the closest that the Pokémon world has to a god.
Red will be the first name on the lips of Pokémon fans, in terms of a Trainer who could still beat Ash even in his current rich vein of form. Red appears at the end of the Gen II games, acting as the final boss of the Kanto region, as the Elite Four and Lance did for Johto.
1 Paul Is Ash's Antithesis
In the end, Ash finally won, but not without many humiliating failures. He formed a mutual respect with his polar opposite as the two developed as battlers and people. Defeating Paul after so many losses was Ash's greatest validation of himself and his beliefs.
This Pokémon is fully evolved. Zacian debuted in Sword and Shield, Slumbering Weald!, when Ash encountered it in the Slumbering Weald after getting separated from Goh.
8 Ash - Melmetal
Ash usually befriends (and doesn't catch) Legendaries, making Melmetal one of two big deviations from the rule.
It is Ho-Oh. and about Ho-Oh is in Gen 2, yes in the games, but pokemon happen to appear in earlier regions than the games, for example May catches a muchlax is Hoenn.
Ash's Rayquaza was the sixth Pokémon that Ash caught in Pokémon Journeys: The Series, and his fifty-eighth overall.
Zapdos (Japanese: サンダー Thunder) is a dual-type Electric/Flying Legendary Pokémon introduced in Generation I. It is not known to evolve into or from any other Pokémon.
Charizard and Ash had one of the most intense love-hate relationships. Charizard was by far one of the most rebellious Pokémon that Ash possessed. From the beginning, it was disobedient as it was more skillful than its trainer.
Glalie. After evolving from a nervous Snorunt, Glalie never lost a one-on-one match—although it was forced into a tie on more than one occasion.
2 Torkoal. Torkoal was caught in the Hoenn region and is easily the weakest Fire-type Ash has ever owned. A very emotional Pokémon, it would cry tears of joy or sadness depending on the situation.
Uxie, Mesprit and Azelf are the Lake Guardians of the Sinnoh and, despite being the only legendary Pokémon to appear in the wild outside of events and Daily Adventure Incense, they're three of the rarest Pokémon in the game.
Although many other Pokemon have the ability to Mega Evolve and also benefit from the same 100 stat point bonus after doing so, Mewtwo and Rayquaza are tied when it comes to the strongest Pokemon that have access to Mega Evolution.
Pikachu not only was his first pokémon but has stuck by his side through every journey across all regions.
What was the first rare Pokémon Ash saw? He saw Ho-Oh when he started his Kanto journey. He saw Suicune on the first day of his Johto journey. He later saw Ho-Oh which prompted him to head to Hoenn.
The young boy's name is Ash Ketchum. Or, at least, it is in English-language versions. In the original Japanese, his name was Satoshi, after the creator of Pokémon, Satoshi Tajiri. He based Ash/Satoshi on his childhood self; his early fascination with catching bugs inspired the premise of Pokémon.