Mesprit is part of the Psychic legendary trio that debuted in Pokemon Diamond / Pearl. Each one guards one of Sinnoh’s three lakes.
Pokemon Diamond / Pearl / Platinum – Once you’ve beaten Team Galactic at Mt. Coronet, the lake trio of legendaries (Azelf, Mesprit and Uxie) will become available. Of the three lake Pokemon, Mesprit is the hardest to catch, since it’s the only one that roams Sinnoh instead of staying at its respective lake. First, go to Lake Verity and approach Mesprit, who will immediately flee and begin roaming/teleporting all over Sinnoh. Use your Marking Map Poketch app to view his current location. You don’t have to go after him right after your initial encounter – in fact, once Mesprit begins to roam Sinnoh, you can save your game and then go after him whenever you feel like it. Roaming Pokemon are the most irritating Pokemon to catch, so here are a few tips:
-Using Fly to get closer to Mesprit usually doesn’t work. You’ll have to walk/bike there and hope he doesn’t move again while you’re en route.
-Have a Pokemon with the Mean Look move at the head of your party (Crobat is a good candidate because of his high speed stat) and use it right away to prevent Mesprit from fleeing.
-Better yet, have a Wobbuffet at the head of your party. Its Shadow Tag ability will prevent Mesprit from fleeing even if Wobbuffet switches out.
-Mesprit’s HP doesn’t regenerate between encounters, so if you’ve gotten its health down and it flees, its health will still be down next time you encounter it.
Mesprit and Cresselia are both good candidates for using your Master Ball.
Pokemon Black / White 2 – After completing the game, visit the Cave of Being and watch as the three Legendary fairy Pokemon fly to different locations around Unova. Mesprit can be found at the top of Celestial Tower.
Trivia: Mesprit and Kirlia have the same species name – Emotion Pokemon.
Still a fan favorite after all these years, Mew is a Psychic-type Pokemon prized for its versatility.
My Pokemon Ranch – This is only way to obtain Mew on your own through normal gameplay. Once your ranch reaches level 25 (meaning you’ve deposited 999 Pokemon into the ranch), Mew will be available for trade. Hayley (the ranchkeeper character) will trade you a Mew for ANY egg. If you check your ranch everyday and deposit as many fodder Pokemon as you can, you’ll reach level 25 in no time, especially since each day that you check the ranch, Hayley will also add to the ranch’s Pokemon total by depositing some of her own Pokemon.
Trivia: Mew is the only Pokemon that can learn every TM/HM move.
This Psychic-type Pokemon is classified as a Genetic Pokemon, and was one of the stars of the very first Pokemon movie.
Pokemon HeartGold / SoulSilver – To capture Mewtwo in these games you'll first need to obtain all the Kanto badges to unlock access to the Cerulean Cave. Once you're in the cave it's almost identcal to the FireRed / LeafGreen encounter. It's a tough dungeon and a tough battle with a level 70 Mewtwo, so make sure to bring your strongest Pokemon.
Pokemon FireRed / LeafGreen – Mewtwo can be found in Basement 1 of Cerulean Cave. To get there, you must first beat the Elite 4 and complete the Sevii Islands quest. After you’ve done that, Fly to Cerulean City and head north across Nugget Bridge and use Surf once you get to the river. Travel along the river until south until you reach Cerulean Cave. Since this is an advanced quest, this dungeon is quite difficult without a strong party of Pokemon. You’ll find Mewtwo at level 70 on the bottom floor of the cave. Annoyingly, Mewtwo knows the move Recover, allowing it to recover HP and making it all the more difficult to catch. Do yourself a favor and just use your Master Ball, or at the very least make sure you have a Pokemon in your party that can put him to sleep.
Trivia: Mewtwo has the highest special attack stat of any non-event Pokemon. Deoxys’s Attack form is the only Pokemon that surpasses it.
One of the three legendary birds from Generation I, Moltres is the Fire/Flying type third of the trio.
Pokemon HeartGold / SoulSilver – Moltres appears inside the Silver Cave between Johto and Kanto once you've earned all 16 badges. Moltres is around level 50 during this encounter.
Pokemon Platinum – Once you get the National Dex, the three legendary birds (Articuno, Moltres and Zapdos) will be roaming Sinnoh in the same way that Cresselia and Mesprit jumped around from place to place. Use your Marking Map Poketch app to see their current locations and track them down. Once the encounter begins, use a Pokemon with the Mean Look move to prevent each bird from fleeing (or better yet, use a Wobbuffet – its Shadow Tag ability will automatically prevent the bird from fleeing, even if you switch it out) and you should have all three in no time.
Pokemon LeafGreen / FireRed – Moltres can be found on One Island in the Sevii Islands area. Make sure you have a Pokemon with the HMs Surf, Strength and Cut before proceeding. If you haven’t already, head to the Pokemon Center on Cinnabar Island and tell Bill you want to visit the Islands. Get the Tri-Pass from Bill which allows you to travel to Islands One, Two and Three anytime. Then head East using Surf to Island One. You’ll find Moltres inside Mt. Ember.
Pokemon XD – Moltres can be caught during the boss battle against Grand Master Greevil on Citadark Island. This is a pretty tough boss battle and it’s fairly difficult to catch the legendary birds this way. Since the bird trio is now available on Platinum and HG / SS there’s really no reason to go back to XD, unless, of course, you really want to.
Trivia: When Moltres was introduced in Generation I, it had the highest base stat total among the three legendary birds (495 for Moltres, vs Articuno at 485 and Zapdos at 490).
The cover star of Pokemon Pearl, this Water/Dragon type’s powers are amplified with the use of the Lustrous Orb.
Pokemon HeartGold / SoulSilver – Palkia can be obtained in HG / SS though it requires an Arceus to do so. With Arceus in the first spot in your party, visit the Ruins of Alph and Cynthia should appear. Talk to her and you will be warped to a place called the Sinjoh Ruins where you will be allowed to have Arceus create one of the following legendary pokemon: Dialga, Palkia or Giratina. Pokemon received through this event arrive holding their respective orb, in this case the Lustrous Orb, and are level 1.
Pokemon Pearl – If you’re playing through Pearl, Palkia is a total no-brainer since you must encounter it as part of the plot. When you finally make it through Mt. Coronet, after your big boss battle with Cyrus, Palkia will be waiting for you to battle and capture. After you capture it, make sure you walk past where it was standing and pick up the Lustrous Orb, which is an essential hold item to maximize Palkia’s power.
Pokemon Platinum – Palkia will be at Spear Pillar, but you won’t be able to battle it until you’ve obtained the National Dex and returned to Spear Pillar after your initial encounter there with Cyrus and Giratina.
Note that you’ll encounter Palkia at level 47 in Pearl, and an impressive level 70 in Platinum.
Trivia: Palkia is one of only two dual-type Water/Dragon Pokemon – the other is Kingdra.
Let it be known that we’re including Phione in this guide under extreme protest. By any empirical measure, Phione should NOT be classified as a legendary. Unfortunately, the official word from Pokemon.com is that Phione is indeed a legendary, and we can’t argue with official word (*cough* even though it’s wrong). Phione is easily the easiest of all legendaries to obtain, because Phione is the only Legendary that’s obtainable through breeding.
Pokemon Diamond / Pearl / Platinum / HeartGold / SoulSilver / Black / White – Breed a Manaphy with a Ditto to obtain a Phione offspring.
My Pokemon Ranch (WiiWare) – Hayley will trade you a level 50 Phione for a Leafeon once your ranch reaches level 15.
Trivia: Phione has the lowest base stats of any legendary.