This Fire/Steel Pokemon introduced in Diamond / Pearl is a quadrupedal powerhouse.
Pokemon Diamond / Pearl / Platinum – Heatran resides in Stark Mountain on the northeastern island area. After beating the Elite 4, Fly to Snowpoint City and talk to the man to the south at the boat dock, who will take you to the Fight Area of the island (or if you’ve already been to the areas on the island, just Fly directly to the Survival Area). Make sure you have a Pokemon in your party that knows Surf, Rock Climb, Rock Smash and Strength. If you’re starting from the Fight Area, head north on Route 225 to the Survival Area. From there, go east along Route 226. Climb up the hill and Surf across the pond, then continue north on Route 227 which leads you to the entrance to Stark Mountain.
If this is your first time visiting Start Mountain, you’ll have to go through some story stuff with Rival and Buck first, and navigate through the mountain with Buck tagging along. Once you’re done with all the story stuff (which requires going back to the Survival Area to talk to Buck again), head back to Stark Mountain and go back to where you found the Magma Rock, and Heatran will be waiting for you there.
Some notes from our Diamond/Pearl advanced guide:
It’s a Fire/Steel type, making it strong or immune to the vast majority of techniques. Electric attacks deal normal damage, while Fighting and Water skills will be considerably more effective. Heatran’s major weakness is Ground attacks, but be careful, because it’s quite possible to one-hit faint it with a single strong Ground skill. One important point is to never, ever use Fire skills when fighting Heatran. You might think Fire attacks would be good for getting Heatran’s HP low, but Heatran can absorb all fire attacks with its Flash Fire skill – and every attack it absorbs makes its Fire techniques even stronger!
Heatran’s attacks are primarily Fire-based. Fire Spin is fairly weak, but will prevent you from switching out the Pokemon currently in battle. Lava Plume is much stronger, and carries a risk of burning the pokemon it hits. Scary Face severely reduces your pokemon’s speed, and Heatran will use it often, so you should expect to be going second most of the time. To effectively counter and stall against Heatran, you’ll want to pick a poke that can both withstand its attacks and hit at its weaknesses. Infernape and Combusken are good choices for a combination of good offense and defense, while Water/Rock pokemon such as Relicanth, Kabutops, and Omastar work well as pure tanks.
Pokemon Black / White 2 – Heatran is found in the basement area of Reversal Mountain. The Magma Stone found in Route 18 is required.
Trivia: With a 50/50 male/female gender ratio, Heatran is the only legendary that can be either male or female. Not that it matters all that much, being unbreedable and all.
This majestic Fire/Flying type Pokemon is the cover start of Pokemon Gold, and has the species designation of Rainbow Pokemon.
Pokemon HeartGold / SoulSilver – Ho-Oh is kind of hard to miss in HeartGold as you'll be encountering it via the game's main story. After defeating the Kimono Girls and Team Rocket you'll get the Rainbow Wing. Take this item to the top of the Bell Tower in Ecruteak City and you'll battle a level 45 Ho-Oh.
Ho-Oh is also obtainable in SoulSilver though you'll have to get the Rainbow Wing from a man in Pewter City. The Ho-Oh you encounter in this case will be level 70.
Pokemon Colosseum – After beating all 100 trainers in all 12 colosseums, complete either of the Mt. Battles (single or double battle) and you’ll be rewarded with a level 70 Ho-Oh as a prize. This is no easy task, but unfortunately it’s the only legitimate non-event way to obtain Ho-Oh on your own through normal gameplay.
Pokemon FireRed / LeafGreen / Emerald – By event only. You would have needed a Mystic Ticket to get to Navel Rock, where Ho-Oh resides. If you didn’t initially get this at one of the official events, you’re out of luck.
Trivia: Oddly, Ho-Oh appeared in the very first episode of the Pokemon TV show, making it the first Generation II Pokemon ever seen (although it wasn’t actually identified until much later).
This super cute Steel/Psychic type always has the ability Serene Grace, which doubles the usual chance for a move’s added effect to occur.
Pokemon Colosseum Bonus Disk (North America only) – If you can get your hands on a copy of the Colosseum Bonus Disc, which was given out to those who preordered Colosseum, this is by far the easiest way to obtain Jirachi on your own. With the Bonus Disc, you can actually transfer as many Jirachis as you want to either Ruby or Sapphire, as long as there’s not currently a Bonus Disc Jirachi on that cart. So technically, you can download a Jirachi on Ruby, transfer that Jirachi to Sapphire, then repeat the process as many times as you want until your Sapphire cart is filled with Jirachis. The OT for this Jirachi is WISHMKR.
Pokemon Channel (Europe and Australia only) – In the European and Australian versions of the GameCube spin-off game Pokemon Channel, Jirachi can be obtained after completing the game. The OT for this Jirachi is CHANNEL, and it can be transferred to Ruby or Sapphire.
Trivia: Jirachi is one of only two Pokemon (the other being Manaphy) that has no in-game location in any of the main series of games.
When it is resolute, its body fills with power and it becomes swifter. Its jumps are then too fast to follow.
Keldeo is an event-only Pokemon that was available from August 27 to October 6 in the US GameStop events.
The cover star of Pokemon Sapphire, this Water-type Pokemon looks like a futuristic orca.
Pokemon HeartGold – After obtaining the National Dex and getting the Kanto starters from Professor Oak, obtain the Blue Orb by visiting Mr. Pokemon. Head to Route 47 and enter the Embedded Tower with the orb and you'll encounter Kyogre who's around level 50. Note you'll have to trade with a SoulSilver player to get Groudon.
Pokemon Sapphire – Kyogre can be found in the Cave of Origin, which you’ll encounter while playing through the main game. To get there, start at Sootopolis City. To the northeast of the Poke Mart, you’ll see a guy named Stephen. Talk to him and eventually he’ll lead you to the entrance of the Cave of Origin. You’ll find Kyogre right inside.
Pokemon Emerald –You’ll find Kyogre in Marine Cave this time around. To find Marine Cave, you’ll have to Fly to Fortree City and then go west to Route 119. Follow the path until you get to the Weather Institute. Go to the second floor and talk to the dude there who’ll tell you about the weather. He’ll either tell you about a drought or a downpour on a certain route. To get Kyogre, you want him to mention downpour. Exiting and reentering the building resets what he says, so if you have to, exit and reenter until he mentions a downpour. Go to the route he mentions (it’ll be either 114, 115, 116 or 118). You’ll find the entrance to Marine Cave there and Kyogre will be inside at level 70.
Trivia: Kyogre has its own boss stage in Pokemon Pinball: Ruby & Sapphire (GBA), which is an awesome game. Kyogre’s counterpart Groudon has its own stage too.
With its unique Dragon/Ice typing and incredible stats, Kyurem is worth venturing deep into the Giant Chasm to obtain.
Pokemon Black / White – Kyurem is located within Giant Chasm. Venture deep into this dangerous area to find the legendary Pokemon Kyurem. Giant Chasm consists of two parts – a cave area and the crater forest it leads to. Make sure you have a Pokemon that knows Surf, and head through the cave until you reach the forest. This is where it gets tricky, because hopping off the wrong ledge can send you back to the beginning. Make your way through the forest in a clockwise spiral, starting at the outer edges and working in. Make sure you have plenty of Dusk Balls and same your game before approaching legendary Dragon/Ice type Kyurem. At level 75 with powerful moves like Glaciate and Dragon Pulse, you've got your work cut out for you.
Pokemon Black / White 2 – After capturing Zekrom or Reshiram from Dragonspiral Tower, Kyurem can be found in the northern-most cave in Giant Chasm. Kyurem can be used in its normal form or it can be used as Black Kyurem or White Kyurem if merged with Zekrom or Reshiram.
Trivia: Reshiram and Zekrom represent yin and yang, whereas Kyurem, the third member of B&W's dragon trio, represents wuji, the absence of yin and yang.