In the first tunnel, take pictures of the purple myst that floats around. When they develop, It will be one of the ghost trio (Gastly, Haunter, Gengar).
Group of Charmanders
To find a group of Charmander, go to to the place where you can find the Moltres egg. The pelt the egg with pokemon food, and if you've recieved pester balls, throw those. Then you'll see a Charmander call his buddies. From then on, it's a waiting game. After the Charmander come, take a picture and you'll recieve bonus points from Professor Oak.
To Get Mew
First you'll need to get all of the signs in the levels. Then Oak will tell you about the Rainbow Cloud. You can go there and that's where you will find Mew. You'll see him in a bubble. Throw pester balls at the bubble and when it breaks Mew will fly away. Look to the left and you should see Mew trying to get back in its bubble. Quickly take a picture of it.
Dragonite
In the valley stage, when you get to the whirlpool, throw some pester balls into it and Dragonite will appear.
Get Muk
In the Cave there are two grimers. Take lots of pictures of them. When the third appears near the three bulbasaurs, take a picture. Now throw lots of pester balls at him. He will evolve into Muk.
How to hit the River Switch
At the beginning of the level, throw pesterballs at the squirtles to make them leave the river. Further down the river you'll find the squirtles sunning themselves at the base of a steep hill. At the top is a mankey. As you pass the squirtles, throw pesterballs at them, causing them to roll up the hill. If your timing is right, the mankey will fall down and land near the switch. As you approach the switch, throw another pesterball at the mankey, knocking him backwards onto the switch.
Mythical Birds
Each of the three birds will be in an egg.
The first Mythical bird is Moltres (he is in the Volcano level), he will be easy to find since his egg is blocking your path. all you have to do is hit the egg with pokemon food or pester balls and a moltres will emerge from the hot lava
To get Zapdos you must lure pikachu to the egg sitting in the tunnel then play a pokeflute. If you did it right pikachu will hit the egg and he will shoot the egg out and the egg will blow up revealing Zapdos.
Articuno: Play your Pokeflute when you see the Jynx and the egg.
Posing Pikachus
It seems everyone's favorite Pokemon is just looking for a photo op. Here's some locations for some very special photographs.
To see Pikachu rolling on a ball go to the Tunnel. When you start the stage take pictures of the Pikachu immediately. He should move farther down. Keep taking his picture. He will stop and jump on a rolling Electrode.
To see Speed Pikachu go to the River. At the very end on your left you should see Pikachu hiding behind a tree. Throw an apple at Pikachu and it should fall down. Then he will run back and forth as the Speed Pikachu.
To see Pikachu surfing go to the Beach. Throw apples at the first Pikachu you see. Throw the apples on the right side of your tracks. There will be a surf board there so try to lead him there. If you do it right he will surf.
To see Pikachu on a stump go to the Beach stage. The first time you see Meowth chasing a pidgey out of the long grass, throw pester balls into the long grass to get Scyther. After you get Scyther, 2 Pikachus should come out to the stump on your left side. Lead them with apples and play the poke flute.
In the cave, towards the end, you will see a zubat carrying Pkachu. Hit the zubat with apples and pesterballs until he drops Pikachu. Pikachu will sprout balloons and fly away.
Save Pikachu from the Zubat in the Cave and awaken Articuno from his egg by playing the Pokeflute. When you get to the end of the level next to where Jigglypuff's stage is, turn around and you'll see Pikachu riding on Articuno.
Dancing charmanders
After you get the charmanders by you in the volcano, get them to come near you and play the poke flute.(prof. oak wont give you special points for this but it's fun just the same.)
Magenite
In the volcano level throw apples and they should come together and before they come together you should be able to get a good shot of one of the three.
Arcanine
Near the end where you see Charmeleon around the lava pool, look to the right. You will see three little lava pools. Toss Pester Balls into all three of them and you can get a picture of arcanine. You can get Arcanine to come out of the first two lava pits or the last one. Try to get a picture of Arcanine when it's shaking embers of its body. You get extra points for this.
Get Charizard
When you get at the end of the volcano level you will see Charmeleon running around a lava pit. Knock him in it with a apple or pester ball and he will come back out as Charizard.
Getting Slowbro
Across the river (in the River) from where Vileplume is (or you may see it before that) there will be a Slowpoke on the grass. Like when you get Pikachu to move in the Tunnel to free Zapdos, you need to throw apples to lure Slowpoke near the Shellder sign. It will turn around. and dip its tail in the water. When it lifts the tail up get your camera ready because when Shellder hits Slowpoke's tail, Slowpoke will evolve into Slowbro.
Speed Pikachu
Right before you leave The River, you will see a Pikachu sitting on a fallen tree branch. If you hit it with either a Pester Ball or an Apple it will fall backwards. Get your camera ready because it will zoom around that area so get a close picture right after you hit it.
Advanced forms
There are advanced forms of some pokemon like Lightning Picachu and Surfing Picachu and Singing Jiggly Puff. These will get you higher scores than just a plain one.
Helpful Hint
It is easy to get a picture of a pokemon, but if you want a high score then you should try to get a picture with more then one pokemon and one if them in the center.