Here's some artices on how to catch pokemon featured by: Flygonkid and jperson123.

Non-Legendary Pokemon

Drifloon

Drifloon will appear in Valley Windworks after you have defeated Mars there. It only appears on Friday, but it isn't in the grass. It is in sprite-form like any other NPC poke or trainer. Press A when facing it to battle. But if it is Saturday, you can get Drifloon until 6 more days pass. So you set your DS's clock to Thursday. Why Thursday? Because Diamond and Pearl makes you wait an extra 24 hours for any timed based events if you mess with the DS. Also, if you just need one for your Dex, one of the trainers in the Hearthome Gym has one.


Legendary Pokemon



Diagla/Palkia

These pokemon can be found on the top of Mt. Coronet. AFter you defeat the Galactic Grunts, Admins, and Boss, you can catch Palkia(Pearl) or Diagla(Diamond). The the legendary trio appears, Diagla/Palkia is awakened and you can fight. Your pokemon are not healed or anything. They are at Lv. 47.


Heatran

The first time you go up to Stark Mountain,Bucky, the red-haired dude is there. You double team with him to get to the end of the mountain. There is nothing in the room where Heatran should be,but the Lava Stone.Bucky decides to take it, and returns to his home in Survival Area. When you go to his home, he says that the Lava Stone woke up a pokemon. Then he runs off to put the Lava Stone back. When you go back to the room where the Lava Stone originally was, Heatran is there, ready to battle.


Regigigas

Regigigas can be found in the temple north of Snowpoint City. He can't be reached until yoou have transfered all the other Regis(Regice,Registeel,Regirock) from your R/S/E game. You need to have each one of those in your team, and go to the bottom of the temple. There you can reach Regigigas and awake him. Then you battle him, a very strong pokemon at lv. 70.


Giratina

Once you have beaten the Pokemon league and obtained the national dex, you will see a new path open up south of Hearthome City! This path is called the Spring Path, you will walk in there and the wild Pokemon will be about level 50. If you keep going you will see a new cave called the Turnback Cave. When you enter it you have to go through a frustrating maze, but, once you have gotten through the maze you will encounter the Lv. 70 Giratina! It's signature move is called Shadow Force. The best type to use on Giratina is ice and dragon. ---By jperson123


Cresselia

After you get the National Dex, go to the Sailor's house by the boat in Canalave Town. The little kid there is sick, and you will be told to go to Full Moon Island. Talk to the sailor outside at he will take you there. Cresselia is the only thing there. Talk to it, and just like Mesprit, it will fly away. Also like Mesprit, look at your PokeTech to find where it is.


Phione/Manaphy

Manaphy is obtainable after getting the special egg from Pokemon Ranger. After you've transfered the egg over to you game, hatch it, and it'll be a Manaphy on lv. 1. When you breed it and it hatches, the pokemon will be the weaker form of Manaphy; Phione.


Event Pokemon


Darkai

After obtaining the item Membership Pass, go to the hotel in Canalave City that was previously locked. When you go there for a night's sleep, you will be disturbed by Darkrai. When you wake up, there will be a journal, containing Darkrai's location. Go to the sailor by the ship and he will take you there. When you get there, go and battle Darkai. He is at level 40.


Shaymin

After you recieve the item Oak's Letter, go to the White Rock in Route 224. There will be an extended part of it. This route is very long, and at the end is Flower Paradise. There you will find Shaymin, waiting at lv. 30.


Arceus

Once you go to the event and obtain the item Heaven's Pipe, you can catch Arceus. While this is in your bag, go to the peak of Mt. Coronet; where you caught/saw Diagla/Palkia. Go to the symbol between the two pillars and use the Heaven's Pipe. Now some stairs will appear, and go down them to find Arceus. It is a very high leveled pokemon, and on level 80.

I hope you like these and get to use them!

~Giratina by jperson123, the rest by flygonkid