Legendary pokemon are arguably the most useful pokemon in Pixelmon. In order to catch these rare pokemon, it is essential to know where each one spawns, as they all have specific spawn zones.
Legendary pokemon spawn very rarely, and in their own specific biomes. As of the latest update, the rarest legendary to find is Mewtwo, with a spawn rate of 1/10000. Mew, Mewtwo, Rayquaza,the three legendary bird pokemon, Groudon and Kyogre are the only legendaries currently in the game. Here is a list of the biomes in which the legendaries spawn as of 3.0.0:
- Articuno: Frozen Shrine
- Zapdos: Static Shrine
- Moltres: Fiery Shrine
- Mew: Jungle Trees
- Mewtwo: Extreme Hills and Cloning Machine
- Rayquaza: Plains
- Groudon Deserts and Desert Hills
- Kyogre Ocean
Obviously, the best place to look for legendaries is the Extreme Hills biome, as that is where most of them spawn. An awesome feature of Pixelmon is that, unlike the actual Pokemon game, legendaries spawn more than once, so you can finally have that all-Mewtwo team you've always wanted.
Also, you can spawn in legendaries with the /pokespawn command.
As of right now. Kyogre doesn't spawn unless you use /pokespawn command or modify the database of Pixelmon to make it spawn.
As legendaries are increasingly hard to catch by order of rarity, it is recommended that you use Master Balls to catch these powerful Pokemon. If you have no Master Balls on you, then it is recommended that you fight the legendary Pokemon in order to weaken them, and then use several Ultra Balls to try to capture them. It is not recommended that you use any type of Pokeball other than Master Balls, Ultra Balls and if it's night Dusk Balls to catch legendary Pokemon. But, be warned that legendaries do fight back, so be careful when taking the Ultra Ball path, but you can always go for night time catching so you are able to fully utilize both the Ultra Ball and Dusk Ball. For catching a Mew, you may want to use this strategy.
Throw Nest Balls at a Mew while outside of battle. But then you will have to stand on it, recommended that you create a small room so it may not fly while you desperately try to stand on it. You will catch it within 1-10 Nest Balls .