To catch Heatran
Unlockable Legendary Pokemon Heatran This legendary can be male or female but cannot breed. Get your national dex and go to the island in the north and east. When you get to Stark Mountain, you must team up with someone to go through the place. The trainer will take the item and depart. Head back to the Survival Area, and your "partner" will be inside a house. Talk to her and she'll leave.

You have only one chance to capture Heatran, so save the game first. Return to the mountain, and Heatran will be waiting. The pokemon is at level 70. Heatran can learn the following moves:
# Level 1 - Ancientpower
# Level 9 - Leer
# Level 17 - Fire Fang
# Level 25 - Metal Sound
# Level 33 - Crunch
# Level 41 - Scary Face
# Level 49 - Lava Plume
# Level 57 - Fire Spin
# Level 65 - Iron Head
# Level 73 - Earth Power
# Level 81 - Heat Wave
# Level 88 - Stone Edge
# Level 96 - Magma Storm